Polycarpus loves lucky numbers. Everybody knows that lucky numbers are positive integers, whose decimal representation (without leading zeroes) contain only the lucky digits x and y. For example, if x = 4, and y = 7, then numbers 47, 744, 4 are lucky.

Let's call a positive integer a undoubtedly lucky, if there are such digits x and y (0 ≤ x, y ≤ 9), that the decimal representation of number a (without leading zeroes) contains only digits x and y.

Polycarpus has integer n. He wants to know how many positive integers that do not exceed n, are undoubtedly lucky. Help him, count this number.

Input

The first line contains a single integer n (1 ≤ n ≤ 109) — Polycarpus's number.

Output

Print a single integer that says, how many positive integers that do not exceed n are undoubtedly lucky.

Examples

Input

10


Output

10


Input

123


Output

113

Note

In the first test sample all numbers that do not exceed 10 are undoubtedly lucky.

In the second sample numbers 102, 103, 104, 105, 106, 107, 108, 109, 120, 123 are not undoubtedly lucky.
import java.io.*;
import java.math.BigInteger;
import java.util.*;
 
 
 
 public class Main {
	public static InputReader in;
    public static PrintWriter pw;
 
 
 
	public static void main(String args[]) {
		new Thread(null, new Runnable() {
            public void run() {
                try{
                    solve();
                }
                catch(Exception e){
                    e.printStackTrace();
                }
            }
        }, "1", 1 << 26).start();
    }
	static ArrayList<Integer> g[];
	static ArrayList<Integer> h[];
	static boolean visited[];
	static boolean visit[];
	static int par[];
	static int degree[];
	static int edjes=0;
	static int start=-1;
	static int end=-1;
	static int Total=0;
	static int time1[];
	static int time2[];
	static int glob=0;
	static long a[];
	static boolean vis2[][];
	static int lev=1;
    static int depth[];
    static long[] sm;
    static int n;
    static int pre[][];
    
   static Stack<Integer> tt=new Stack();
    public static void solve(){
		
	
		 in = new InputReader(System.in);
	 	 pw = new PrintWriter(System.out);
	
 int n=in.nextInt();
 String tle=""+n;
 int ans=0;
 HashSet<Long> set=new HashSet();
 for(int i=0;i<=9;i++)
 {
	 for(int j=1;j<=9;j++)
	 {
		 Queue<String> Q=new LinkedList();
		 Q.add(""+i);
		 Q.add(""+j);
		 HashMap<Long,Integer> bool=new HashMap<Long,Integer>();
		 bool.put((long)i,1);
		 bool.put((long)j,1);
		 while(!Q.isEmpty())
		 {
			 int cnt=Q.size();
			 while(cnt>0)
			 {
			    String s=Q.poll();
			  
			    if(s.length()>tle.length())
			    {
			    	Q.clear();break;
			    }
			    if(Long.parseLong(s)<=n){
			    //	System.out.println(Integer.parseInt(s));
			    	set.add(Long.parseLong(s));
			    	ans++;
			    }
			    String g=s;
			    s+=i;
			    if(!bool.containsKey(Long.parseLong(s)))
			    {
			    	bool.put(Long.parseLong(s), 1);
			    	Q.add(s);
			    }
			    g+=j;
			    if(!bool.containsKey(Long.parseLong(g)))
			    {
			    	bool.put(Long.parseLong(g), 1);
			    	Q.add(g);
			    }
			    cnt--;
			 }
		 }
	 }
 }
		System.out.println(set.size()-1);	
		//System.out.println(set);
    }
    
    
    public static int LCA(int p,int q)
    {
    	if(depth[p]<depth[q])
		{
			int tmp=p;
			p=q;
			q=tmp;
		}
		int dist=depth[p]-depth[q];
		while(dist>0)
		{
			int raise=(int)(Math.log(dist)/Math.log(2));
			p=pre[p][raise];
			dist-=(1<<raise);
		}
		if(p==q)
		{
			return p;
		}
		else{
		
		int current=(int)(Math.log(depth[p])/Math.log(2));
		for(int j=current;j>=0;j--)
		{
			if(pre[p][j]!=0&&pre[p][j]!=pre[q][j])
			{
				p=pre[p][j];
				q=pre[q][j];
			}
		}
		}
	return par[p];
    }
    
public static void dfs(int curr,int lev,int parent)
{
     visited[curr]=true;
     depth[curr]=lev;
     par[curr]=parent;
     for(int x:g[curr])
     {
    	 if(!visited[x])
    	 {
    		 dfs(x,lev+1,curr);
    	 }
     }
     
}


	



	public static int countNumber(int n)
    {
        int result = 0;
     
        // Pushing 1 to 9 because all number from 1
        // to 9 have this propert.
        for (int i = 1; i <= 9; i++)
        {
            Stack<Integer> s=new Stack();
            if (i <= n)
            {
                s.push(i);
                result++;
            }
     
            // take a number from stack and add
            // a digit smaller than last digit
            // of it.
            while (!s.empty())
            {
                int tp = s.peek();
                s.pop();
                for (int j = tp%10; j <= 9; j++)
                {
                    int x = tp*10 + j;
                 //   System.out.println(x);
                    if (x <= n)
                    {
                        s.push(x);
                        result++;
                    }
                }
              //  System.out.println();
            }
        }
     
        return result;
    }
    public static boolean IsPrime(long l) {
		// Corner cases
		if (l <= 1)
			return false;
		if (l <= 3)
			return true;
 
		// This is checked so that we can skip 
		// middle five numbers in below loop
		if (l % 2 == 0 || l % 3 == 0)
			return false;
 
		for (long i = 5; i * i <= l; i = i + 6)
			if (l % i == 0 || l % (i + 2) == 0)
				return false;
 
		return true;
	}
 
     
        
     
        

   
/*public static void dfs2(int curr,int lev)
{
	time1[curr]=glob++;
	
	depth[curr]=lev;
	visited[curr]=true;
	nodes[lev].add(time1[curr]);
	values[lev].add(a[curr]);
	for(int x:g[curr])
	{
		if(!visited[x])
		{
			dfs2(x,lev+1);
		}
	}
time2[curr]=glob++;
}
 
 
 
public static void bfs1(int curr)
{
Queue<Integer> Q=new LinkedList<Integer>();
Q.add(1);
visit[1]=true;
int lev=2;
levels[1].add(1);
while(!Q.isEmpty())
{
	int cnt=Q.size();
	while(cnt>0)
	{
		int p=Q.poll();
		visit[p]=true;
		for(int x:g[p])
		{
			if(!visit[x])
			{
				Q.add(x);
				levels[lev].add(x);
			}
		}
		cnt--;
	}
	max=Math.max(lev, max);
	lev++;
}
}
 
 
	
 	private static long fact(int len) {
	long ans=1;
	for(int i=1;i<=len;i++)
		ans*=i;
	return ans;
}
 */
 
 
	
	// SubTree Checker DFS (TO CHECK IF X IS IN A SUBTREE OF Y)
	public static void dfs3(int curr)
	{
		visited[curr]=true;
		time1[curr]=glob++;
		for(int x:g[curr])
		{
		if(!visited[x])
			dfs3(x);
		}
		time2[curr]=glob++;
	}
    
	
	
 
    /*NO OF EDJES IN WHOLE CONNECTED COMPONENTS
  
	public static void dfs1(int curr)
	{
		visited[curr]=true;
		for(int next:g[curr])
		{
			edje++;
			if(!visited[next])
				dfs1(next);
		}
	}
	/*SUM OF ALL SUBTREE NODE'S VLAUES DFS
	public static void dfs(int curr,int prev)
		{
		val[curr]=1;
			for(int x:g[curr])
			{
				if(x!=prev)
				{
		            dfs(x,curr);
		            val[curr]+=val[x];
					
			    }
			}
		}*/
	
		public static long power(long a,long b)
		{
			long result=1;
			while(b>0)
			{
				if(b%2==1)
					result*=a;
				a=a*a;
				b/=2;
			}
			return result;
		}
				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;
	}
	static class Pair implements Comparable<Pair>{
	int now;
		int aft;
		int index;
		Pair(int ver,int weight,int index){
	     	this.now=ver;
			this.aft=weight;
			this.index=index;
			
		}
		@Override
		public int compareTo(Pair o) {
			if((o.now-o.aft)-(now-aft)!=0)
				return (int)-((o.now-o.aft)-(now-aft));

				return (int)(o.now-now);
		}
				
	}
	public static long gcd(long a, long b) {
		  if (b == 0) return a;
		  return gcd(b, a%b);
		}
	static class InputReader {
 
		private InputStream stream;
		private byte[] buf = new byte[8192];
		private int curChar, snumChars;
		private SpaceCharFilter filter;
 
		public InputReader(InputStream stream) {
			this.stream = stream;
		}
 
		public int snext() {
			if (snumChars == -1)
				throw new InputMismatchException();
			if (curChar >= snumChars) {
				curChar = 0;
				try {
					snumChars = stream.read(buf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (snumChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}
 
		public   int nextInt() {
			int c = snext();
			while (isSpaceChar(c))
				c = snext();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = snext();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = snext();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
 
		public long nextLong() {
			int c = snext();
			while (isSpaceChar(c))
				c = snext();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = snext();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = snext();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
 
		public int[] nextIntArray(int n) {
			int a[] = new int[n];
			for (int i = 0; i < n; i++)
				a[i] = nextInt();
			return a;
		}
 
		public String readString() {
			int c = snext();
			while (isSpaceChar(c))
				c = snext();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = snext();
			} while (!isSpaceChar(c));
			return res.toString();
		}
 
		public boolean isSpaceChar(int c) {
			if (filter != null)
				return filter.isSpaceChar(c);
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}
 
		public interface SpaceCharFilter {
			public boolean isSpaceChar(int ch);
		}
	}
}
