Famous Brazil city Rio de Janeiro holds a tennis tournament and Ostap Bender doesn't want to miss this event. There will be n players participating, and the tournament will follow knockout rules from the very first game. That means, that if someone loses a game he leaves the tournament immediately.

Organizers are still arranging tournament grid (i.e. the order games will happen and who is going to play with whom) but they have already fixed one rule: two players can play against each other only if the number of games one of them has already played differs by no more than one from the number of games the other one has already played. Of course, both players had to win all their games in order to continue participating in the tournament.

Tournament hasn't started yet so the audience is a bit bored. Ostap decided to find out what is the maximum number of games the winner of the tournament can take part in (assuming the rule above is used). However, it is unlikely he can deal with this problem without your help.

Input

The only line of the input contains a single integer n (2 ≤ n ≤ 1018) — the number of players to participate in the tournament.

Output

Print the maximum number of games in which the winner of the tournament can take part.

Examples

Input

2


Output

1


Input

3


Output

2


Input

4


Output

2


Input

10


Output

4

Note

In all samples we consider that player number 1 is the winner.

In the first sample, there would be only one game so the answer is 1.

In the second sample, player 1 can consequently beat players 2 and 3. 

In the third sample, player 1 can't play with each other player as after he plays with players 2 and 3 he can't play against player 4, as he has 0 games played, while player 1 already played 2. Thus, the answer is 2 and to achieve we make pairs (1, 2) and (3, 4) and then clash the winners.

/*
 * Author- Priyam Vora
 * BTech 2nd Year DAIICT
 */

        
import java.io.*;
import java.math.*;
import java.util.*;
import javax.print.attribute.SetOfIntegerSyntax;

public class Graph1 {
	private static InputStream stream;
	private static byte[] buf = new byte[1024];
	private static int curChar;
	private static int numChars;
	private static SpaceCharFilter filter;
	private static PrintWriter pw;
	private static long count = 0,mod=1000000007;
	private static TreeSet<Integer>ts[]=new TreeSet[200000];

	public static void main(String args[]) throws Exception {
		InputReader(System.in);
		pw = new PrintWriter(System.out);
		//ans();
		soln();
		pw.close();
	}
	//----------------------------------------My Code------------------------------------------------//

	private static void soln() {

	long n=nextLong();
	int max=0;
	long a[]=new long[500];
	a[0]=1;
	a[1]=2;
	for(int i=2;i<200;i++){
		a[i]=a[i-1]+a[i-2];
		max++;
		if(n>=a[i-1] && n<a[i]){
			System.out.println(max);
			System.exit(0);
		}
	}
	}
	public static double logOfBase(int base,  long num) {
	    return Math.log(num) / Math.log(base);
	}

	private static void primeFactors(int n,int ind,int[] ans)
	{
		int flag=1;
	    // Print the number of 2s that divide n
	    while (n%2 == 0)
	    {flag=0;
	      n = n/2;
	    }
	    if(flag==0) {
	    	
	    	if(ts[2]==null){
	    	ts[2]=new TreeSet<Integer>();
	    	}
	    	else{
	    		if(ts[2].floor(ind)!=null){
	    			//pw.println(ind+"--");
	    			int d1=ts[2].floor(ind);

	    			//pw.println(d1+" d1");
	    			if(Math.abs(ind-ans[ind])> Math.abs(ind-d1))
		    		ans[ind]=d1;
	    			
		    		if(Math.abs(ans[d1]-d1)>Math.abs(ind-d1)){
		    			ans[d1]=ind;
		    		}
	    		}
	    	}
	    	ts[2].add(ind);
	    }
	 
	    // n must be odd at this point.  So we can skip one element (Note i = i +2)
	    for (int i = 3; i <= Math.sqrt(n); i = i+2)
	    {
	    	flag=1;
	        // While i divides n, print i and divide n
	        while (n%i == 0)
	        {
	          flag=0;  
	            n = n/i;
	        }
	        if(flag==0){
	        	if(ts[i]==null){
	    	    	ts[i]=new TreeSet<Integer>();
	    	    	}
	    	    	else{
	    	    		if(ts[i].floor(ind)!=null){
	    	    			int d1=ts[i].floor(ind);
	    	    			if(Math.abs(ind-ans[ind])> Math.abs(ind-d1))
	    			    		ans[ind]=d1;
	    		  
	    		    		if(Math.abs(ans[d1]-d1)>Math.abs(ind-d1)){
	    		    			ans[d1]=ind;
	    		    		}
	    	    		}
	    	    	}
	    	    	ts[i].add(ind);

	        }
	        
	    }
	 
	    // This condition is to handle the case whien n is a prime number
	    // greater than 2
	    if (n > 2)
	    {
	    	if(ts[n]==null){
    	    	ts[n]=new TreeSet<Integer>();
    	    	}
    	    	else{
    	    		if(ts[n].floor(ind)!=null){
    	    			int d1=ts[n].floor(ind);
    	    			if(Math.abs(ind-ans[ind])> Math.abs(ind-d1))
    			    		ans[ind]=d1;
    		    		
    		    		if(Math.abs(ans[d1]-d1)>Math.abs(ind-d1)){
    		    			ans[d1]=ind;
    		    		}
    	    		}
    	    	}
    	    	ts[n].add(ind);

        }
	}
	
	//----------------------------------------THE END----------------------------------------------------------//        	

	static class Pair implements Comparable<Pair>{

		int idx,val;
		Pair(int idx,int val){
			this.idx=idx;
			this.val=val;
		}
		@Override
		public int compareTo(Pair o) {
			// TODO Auto-generated method stub
		//	Sort in increasing order

		
			if(o.idx<idx){
				return 1;
			}
			if(o.idx==idx && o.val<val){
				return 1;
			}else{
				return -1;
			}
			
		}
		
	}

	public static long gcd(long x, long y) {
		if (x % y == 0)
			return y;
		else
			return gcd(y, x % y);
	}
	
	private static int BinarySearch(int a[], int low, int high, int target) {
		if (low > high)
			return -1;
		int mid = low + (high - low) / 2;
		if (a[mid] == target)
			return mid;
		if (a[mid] > target)
			high = mid - 1;
		if (a[mid] < target)
			low = mid + 1;
		return BinarySearch(a, low, high, target);
	}
	
	public static String reverseString(String s) {
		StringBuilder sb = new StringBuilder(s);
		sb.reverse();
		return (sb.toString());
	}
	
	private static int GetRightPosition(int A[], int l, int r, int key) {
		int m;

		while (r - l > 1) {
			m = l + (r - l) / 2;

			if (A[m] <= key)
				l = m;
			else
				r = m;
		}

		return l;
	}

	private static int GetLeftPosition(int A[], int l, int r, int key) {
		int m;

		while (r - l > 1) {
			m = l + (r - l) / 2;

			if (A[m] >= key)
				r = m;
			else
				l = m;
		}

		return r;
	}

	private static int CountOccurances(int A[], int size, int key) {
		// Observe boundary conditions
		int left = GetLeftPosition(A, -1, size - 1, key);
		int right = GetRightPosition(A, 0, size, key);

		// What if the element doesn't exists in the array?
		// The checks helps to trace that element exists
		return (A[left] == key && key == A[right]) ? (right - left + 1) : 0;
	}

	private static int Ceil(int a[], int low, int high, int target) {
		if (target <= a[low]) {
			return a[low];

		}
		if (target > a[high])
			return -1;
		while (high - low > 1) {
			int mid = low + (high - low) / 2;
			if (a[mid] < target) {
				low = mid;
				if (mid + 1 <= a.length - 1 && a[mid + 1] >= target)
					return mid + 1;
			}
			if (a[mid] >= target) {
				high = mid;
				if (mid - 1 >= 0 && a[mid - 1] < target) {
					return mid;
				}
			}
		}
		return -1;
	}

	private static int floor(int a[], int low, int high, int target) {
		if (target < a[low]) {
			return -1;
		}
		if (target >= a[high])
			return a[high];
		while (high - low > 1) {
			int mid = low + (high - low) / 2;
			if (a[mid] > target) {
				high = mid;
				if (mid - 1 >= 0 && a[mid - 1] <= target) {
					return mid - 1;
				}
			}
			if (a[mid] <= target) {
				low = mid;
				if ((mid + 1) <= a.length - 1 && a[mid + 1] > target) {
					return mid;
				}
			}

		}
		return -1;
	}

	
	
	public static long pow(long n, long p, long m) {
		long result = 1;
		if (p == 0)
			return 1;
		if (p == 1)
			return n;
		while (p != 0) {
			if (p % 2 == 1)
				result *= n;
			if (result >= m)
				result %= m;
			p >>= 1;
			n *= n;
			if (n >= m)
				n %= m;
		}
		return result;
	}

	public static long pow(long n, long p) {
		long result = 1;
		if (p == 0)
			return 1;
		if (p == 1)
			return n;
		while (p != 0) {
			if (p % 2 == 1)
				result *= n;
			p >>= 1;
			n *= n;
		}
		return result;

	}
	 static void combinationUtil(int arr[], int data[], int start,
             int end, int index, int r)
{
		 // Current combination is ready to be printed, print it
if (index == r)
{
	HashSet hs=new HashSet();
for (int j=0; j<r; j++)
{
	hs.add(data[j]);
//	pw.print(data[j]+" ");
}
//pw.println();
for(int j=0;j<r;j++){
	if(!((j>0&& hs.contains(data[j]-1)) || (j<data.length-1 && hs.contains(data[j]+1)))){
		return;
	}
}
count++;
count%=1000000007;

return;
}

// replace index with all possible elements. The condition
// "end-i+1 >= r-index" makes sure that including one element
// at index will make a combination with remaining elements
// at remaining positions
for (int i=start; i<=end && end-i+1 >= r-index; i++)
{
data[index] = arr[i];
combinationUtil(arr, data, i+1, end, index+1, r);
}
}

// The main function that prints all combinations of size r
// in arr[] of size n. This function mainly uses combinationUtil()
static long printCombination(int arr[], int n, int r)
{
// A temporary array to store all combination one by one
int data[]=new int[r];

// Print all combination using temprary array 'data[]'
combinationUtil(arr, data, 0, n-1, 0, r);
return count;
}

public static long printSubsets(int set[],boolean prime[]) {
		long ans = 0;
		int n = set.length;

		// Run a loop for printing all 2^n
		// subsets one by obe
		for (int i = 0; i < (1 << n); i++) {
			int a[] = new int[n];

			int count = 0;

			// Print current subset
			for (int j = 0; j < n; j++)

				// (1<<j) is a number with jth bit 1
				// so when we 'and' them with the
				// subset number we get which numbers
				// are present in the subset and which
				// are not
				if ((i & (1 << j)) > 0) {

					a[count] = set[j];
					count++;
					//System.out.print(set[j] + " ");
				}
			int tot = 0;
			for (int t = 0; t < count; t++) {
				tot^=a[t];
				pw.print(a[t]+" ");
			}
			//	System.out.println(tot+" "+sum);
			if (prime[tot]) {
				ans++;
				ans%=mod;
			}
			pw.println();
		} //System.out.println(sum+"-sum "+l+" -l");
		return ans;
	}

	// remove N elements in equal steps starting at specific point
	static List<Integer> josephus(int N, int step, int start) {
		if (N < 1 || step < 1 || start < 1)
			return null;

		List<Integer> p = new LinkedList<Integer>();
		for (int i = 0; i < N; i++)
			p.add(i + 1);

		List<Integer> r = new LinkedList<Integer>();
		int i = (start - 2) % N;
		for (int j = N; j > 0; j--) {
			i = (i + step) % N--;
			r.add(p.remove(i--));
		}

		return r;
	}


	public static int[] radixSort(int[] f) {
		int[] to = new int[f.length];
		{
			int[] b = new int[65537];
			for (int i = 0; i < f.length; i++)
				b[1 + (f[i] & 0xffff)]++;
			for (int i = 1; i <= 65536; i++)
				b[i] += b[i - 1];
			for (int i = 0; i < f.length; i++)
				to[b[f[i] & 0xffff]++] = f[i];
			int[] d = f;
			f = to;
			to = d;
		}
		{
			int[] b = new int[65537];
			for (int i = 0; i < f.length; i++)
				b[1 + (f[i] >>> 16)]++;
			for (int i = 1; i <= 65536; i++)
				b[i] += b[i - 1];
			for (int i = 0; i < f.length; i++)
				to[b[f[i] >>> 16]++] = f[i];
			int[] d = f;
			f = to;
			to = d;
		}
		return f;
	}

	public static int nextPowerOf2(final int a) {
		int b = 1;
		while (b < a) {
			b = b << 1;
		}
		return b;
	}

	public static boolean PointInTriangle(int p1, int p2, int p3, int p4, int p5, int p6, int p7, int p8) {
		int s = p2 * p5 - p1 * p6 + (p6 - p2) * p7 + (p1 - p5) * p8;
		int t = p1 * p4 - p2 * p3 + (p2 - p4) * p7 + (p3 - p1) * p8;

		if ((s < 0) != (t < 0))
			return false;

		int A = -p4 * p5 + p2 * (p5 - p3) + p1 * (p4 - p6) + p3 * p6;
		if (A < 0.0) {
			s = -s;
			t = -t;
			A = -A;
		}
		return s > 0 && t > 0 && (s + t) <= A;
	}

	public static float area(int x1, int y1, int x2, int y2, int x3, int y3) {
		return (float) Math.abs((x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2)) / 2.0);
	}

	public static boolean isPrime(int n) {
		// Corner cases
		if (n <= 1)
			return false;
		if (n <= 3)
			return true;

		// This is checked so that we can skip 
		// middle five numbers in below loop
		if (n % 2 == 0 || n % 3 == 0)
			return false;

		for (int i = 5; i * i <= n; i = i + 6)
			if (n % i == 0 || n % (i + 2) == 0)
				return false;

		return true;
	}

	//merge Sort

	static long sort(int a[])
	{  int n=a.length;
		int b[]=new int[n];	
		return mergeSort(a,b,0,n-1);}
	static long mergeSort(int a[],int b[],long left,long right)
	{ long c=0;if(left<right)
	 {   long mid=left+(right-left)/2;
		 c= mergeSort(a,b,left,mid);
		 c+=mergeSort(a,b,mid+1,right);
		 c+=merge(a,b,left,mid+1,right); }	
		return c;	 }
	static long merge(int a[],int  b[],long left,long mid,long right)
	{long c=0;int i=(int)left;int j=(int)mid; int k=(int)left;
	while(i<=(int)mid-1&&j<=(int)right)
	{ if(a[i]>a[j]) {b[k++]=a[i++]; }
	else	{ b[k++]=a[j++];c+=mid-i;}}
	while (i <= (int)mid - 1)   b[k++] = a[i++]; 
	while (j <= (int)right) b[k++] = a[j++];
	for (i=(int)left; i <= (int)right; i++) 
		a[i] = b[i];  return c;  }
	public static boolean isSubSequence(String large, String small, int largeLen, int smallLen) {
		//base cases
		if (largeLen == 0)
			return false;
		if (smallLen == 0)
			return true;
		// If last characters of two strings are matching
		if (large.charAt(largeLen - 1) == small.charAt(smallLen - 1))
			isSubSequence(large, small, largeLen - 1, smallLen - 1);
		// If last characters are not matching
		return isSubSequence(large, small, largeLen - 1, smallLen);
	}

	// To Get Input
	// Some Buffer Methods

	public static void InputReader(InputStream stream1) {
		stream = stream1;
	}

	private static boolean isWhitespace(int c) {
		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	}

	private static boolean isEndOfLine(int c) {
		return c == '\n' || c == '\r' || c == -1;
	}

	private static int read() {
		if (numChars == -1)
			throw new InputMismatchException();
		if (curChar >= numChars) {
			curChar = 0;
			try {
				numChars = stream.read(buf);
			} catch (IOException e) {
				throw new InputMismatchException();
			}
			if (numChars <= 0)
				return -1;
		}
		return buf[curChar++];
	}

	private static int nextInt() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		int sgn = 1;
		if (c == '-') {
			sgn = -1;
			c = read();
		}
		int res = 0;
		do {
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}

	private static long nextLong() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		int sgn = 1;
		if (c == '-') {
			sgn = -1;
			c = read();
		}
		long res = 0;
		do {
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}

	private static String nextToken() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		StringBuilder res = new StringBuilder();
		do {
			res.appendCodePoint(c);
			c = read();
		} while (!isSpaceChar(c));
		return res.toString();
	}

	private static String nextLine() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		StringBuilder res = new StringBuilder();
		do {
			res.appendCodePoint(c);
			c = read();
		} while (!isEndOfLine(c));
		return res.toString();
	}

	private static int[] nextIntArray(int n) {
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
			arr[i] = nextInt();
		}
		return arr;
	}

	private static int[][] next2dArray(int n, int m) {
		int[][] arr = new int[n][m];
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < m; j++) {
				arr[i][j] = nextInt();
			}
		}
		return arr;
	}

	private static long[] nextLongArray(int n) {
		long[] arr = new long[n];
		for (int i = 0; i < n; i++) {
			arr[i] = nextLong();
		}
		return arr;
	}

	private static void pArray(int[] arr) {
		for (int i = 0; i < arr.length; i++) {
			pw.print(arr[i] + " ");
		}
		pw.println();
		return;
	}

	private static void pArray(long[] arr) {
		for (int i = 0; i < arr.length; i++) {
			pw.print(arr[i] + " ");
		}
		pw.println();
		return;
	}

	private static void pArray(boolean[] arr) {
		for (int i = 0; i < arr.length; i++) {
			pw.print(arr[i] + " ");
		}
		pw.println();
		return;
	}

	private static boolean isSpaceChar(int c) {
		if (filter != null)
			return filter.isSpaceChar(c);
		return isWhitespace(c);
	}

	private interface SpaceCharFilter {
		public boolean isSpaceChar(int ch);
	}

	private static void multiply(int a[][], int b[][]) {
		// Creating an auxiliary matrix to store elements 
		// of the multiplication matrix
		int mul[][] = new int[2][2];
		for (int i = 0; i < 2; i++) {
			for (int j = 0; j < 2; j++) {
				mul[i][j] = 0;
				for (int k = 0; k < 2; k++)
					mul[i][j] += a[i][k] * b[k][j];
			}
		}

		// storing the muliplication resul in a[][]
		for (int i = 0; i < 2; i++)
			for (int j = 0; j < 2; j++)
				a[i][j] = mul[i][j]; // Updating our matrix
	}

	// Function to compute F raise to power n-2.
	private static int power(int F[][], long n) {
		int M[][] = { { 1, 1 }, { 1, 0 } };

		// Multiply it with initial values i.e with
		// F(0) = 0, F(1) = 1, F(2) = 1
		if (n == 1)
			return F[0][0] + F[0][1];

		power(F, n / 2);

		multiply(F, F);

		if (n % 2 != 0)
			multiply(F, M);

		// Multiply it with initial values i.e with
		// F(0) = 0, F(1) = 1, F(2) = 1
		return F[0][0] + F[0][1];
	}

	// Return n'th term of a series defined using below
	// recurrence relation.
	// f(n) is defined as
	//			         	    f(n) = f(n-1) + f(n-2) + f(n-3), n>=3
	// Base Cases :
	//			         	    f(0) = 0, f(1) = 1, f(2) = 1
	private static long findNthTerm(long n) {

		int F[][] = { { 1, 1 }, { 1, 0 } };

		return power(F, n - 2);
	}

}
   
    class MyComp implements Comparator<Integer>{

		@Override
		public int compare(Integer o1, Integer o2) {
			if(o1<o2){
				return 1;
			}else if(o1>o2){
				return -1;
			}
			return 0;
		}

		
    	
    }
    class Graph{
    	private long conse=0,co=0,mac_cons_cat=0;
    	private int V,flag=1, d[], road_cond[][];
    	private Stack <Integer>st=new Stack();
    	private LinkedList<Integer > adj[];
    	private HashMap<String ,Integer> hs =new HashMap<>();
    //	boolean Visited[];
Graph(int V){
	V++;

	
	//this.mac_cons_cat=max_cat;
this.V=(V);
adj=new LinkedList[V];
//for(int i=0;i<V;i++)
	//adj[i]=new LinkedList();

	
//Visited=new boolean[V];
 
}
void addEdge(int v,int w,int t){
	if(adj[v]==null){
		adj[v]=new LinkedList();
	}
	adj[v].add(w);
	String temp="";
temp+=v;
temp+=w;
//System.out.println(temp+"---");
	if(!hs.containsKey(temp))
	hs.put(temp, t);

}
public long  bfs(int s)
{
	co=0;
    // Mark all the vertices as not visited(By default
// set as false)
        boolean visited[] = new boolean[V];
 
        // Create a queue for BFS
        LinkedList<Integer> queue = new LinkedList<Integer>();
 
        // Mark the current node as visited and enqueue it
        visited[s]=true;
        queue.add(s);
 
        while (queue.size() != 0)
        {
            // Dequeue a vertex from queue and print it
    s = queue.poll();
   // System.out.print(s+" ");
 
            // Get all adjacent vertices of the dequeued vertex s
    // If a adjacent has not been visited, then mark it
    // visited and enqueue it
        Iterator<Integer> i = adj[s].listIterator();
        while (i.hasNext())
        {
            int n = i.next();
            if (!visited[n])
            {
                visited[n] = true;
                queue.add(n);
            co++;
            }
        }
        return co;
    }
    return 0;
}
 public long  dfs(int startVertex){
	
	boolean Visited[]=new boolean[V];
	
	//flag=1;
	
	 if(!Visited[startVertex])  {
		
		 co=0; 
		 dfsUtil(startVertex,Visited);
	 
	 }
	 
	 return co;
 }
 public void Connected(int v){
	 Iterator<Integer> i = adj[v].listIterator();
	 while(i.hasNext()){
		 int n=i.next();
		 long data=(long)d[n]+(long)d[v];
		 data=data%1000000007;
		 d[n]=(int)data;
	 }
 }
 public int getByte(int v){
	 return d[v];
 }
private void dfsUtil(int startVertex, boolean[] Visited) {
	//System.out.println(pre+" "+startVertex);

Visited[startVertex]=true;


st.push(startVertex);
while(!st.isEmpty()){
	int top=st.pop();
	System.out.print(top+" ");
	
	//System.out.println(top);
Iterator<Integer> i=adj[top].listIterator();

while(i.hasNext()){
	int n=i.next();
//	System.out.println(n+"---");
			 if( !Visited[n]){
				Visited[n]=true;
					st.push(n);
					co++;
					}
			 }
		
	}
		}
}

class Dsu{
	private int rank[], parent[] ,n;
	
	Dsu(int size){
		this.n=size+1;
		rank=new int[n];
		parent=new int[n];
	makeSet();
	}
	
	void makeSet(){
		for(int i=0;i<n;i++){
			parent[i]=i;
		}
	}
	
	int find(int x){
		if(parent[x]!=x){
			
			parent[x]=find(parent[x]);
		}
		return parent[x];
	}	
	
	void union(int x,int y){
		int xRoot=find(x);
		int yRoot=find(y);
		
		if(xRoot==yRoot)
			return;
		if(rank[xRoot]<rank[yRoot]){
		parent[xRoot]=yRoot;	
		}else if(rank[yRoot]<rank[xRoot]){
			parent[yRoot]=xRoot;
		}else{
			parent[yRoot]=xRoot;
			rank[xRoot]++;
		}
		
	}

}

