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 javax.print.DocFlavor;
import javax.swing.plaf.basic.BasicInternalFrameTitlePane;
import java.io.*;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.nio.Buffer;
import java.sql.BatchUpdateException;
import java.util.*;
import java.util.stream.Stream;
import java.util.Vector;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import static java.lang.Math.*;
import java.util.*;
import java.nio.file.StandardOpenOption;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Iterator;
import java.util.PriorityQueue;

public class icpc
{
    static HashSet<String> A = new HashSet<>();
    public static void main(String[] args)throws IOException
    {
        Reader in = new Reader();

        long n = in.nextLong();
        int len = Long.toString(n).length();
        for(int k=1;k<=len;k++)
        {
            for(int i=9;i>0;i--)
            {
                for(int j=i-1;j>=0;j--)
                {
                    if(j != 0)
                    {
                        generateLucky(Integer.toString(j), k-1, j, i, n);
                        generateLucky(Integer.toString(i), k-1, j, i, n);
                    }
                    else
                    {
                        generateLucky(Integer.toString(i), k-1, j, i, n);
                    }
                }
            }
        }

        System.out.println(A.size());
    }
    private static void generateLucky(String s,int len, int a, int b, long n)
    {

        if(len <= 0)
        {
            if(Long.parseLong(s) <= n)
                A.add(s);
            return;
        }
        String s1 = s + Integer.toString(a);
        String s2 = s + Integer.toString(b);
        generateLucky(s1, len - 1, a, b, n);
        generateLucky(s2, len - 1, a, b, n);
    }
}
class GameComparator implements Comparator<Game>
{
    public int compare(Game ob1, Game ob2)
    {
        if(ob1.x > ob2.x)
            return -1;
        else if(ob1.x < ob2.x)
            return 1;
        return 0;
    }
}
class Game
{
    int x;
    int y;
    Game(int a,int b)
    {
        this.x = a;
        this.y = b;
    }
}
class MergeSort
{
    // Merges two subarrays of arr[].
    // First subarray is arr[l..m]
    // Second subarray is arr[m+1..r]
    void merge(long arr[], int l, int m, int r)
    {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        long L[] = new long [n1];
        long R[] = new long [n2];

        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i)
            L[i] = arr[l + i];
        for (int j=0; j<n2; ++j)
            R[j] = arr[m + 1+ j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1)
        {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2)
        {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    void sort(long arr[], int l, int r)
    {
        if (l < r)
        {
            // Find the middle point
            int m = (l+r)/2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr , m+1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }
}
class Node
{
    String a;
    String b;
    Node(String s1,String s2)
    {
        this.a = s1;
        this.b = s2;
    }
    @Override
    public boolean equals(Object ob)
    {
        if(ob == null)
            return false;
        if(!(ob instanceof Node))
            return false;
        if(ob == this)
            return true;
        Node obj = (Node)ob;
        if(this.a.equals(obj.a) && this.b.equals(obj.b))
            return true;
        return false;
    }

    @Override
    public int hashCode()
    {
        return (int)this.a.length();
    }
}
class Reader
{
    final private int BUFFER_SIZE = 1 << 16;
    private DataInputStream din;
    private byte[] buffer;
    private int bufferPointer, bytesRead;

    public Reader()
    {
        din = new DataInputStream(System.in);
        buffer = new byte[BUFFER_SIZE];
        bufferPointer = bytesRead = 0;
    }

    public Reader(String file_name) throws IOException
    {
        din = new DataInputStream(new FileInputStream(file_name));
        buffer = new byte[BUFFER_SIZE];
        bufferPointer = bytesRead = 0;
    }

    public String readLine() throws IOException
    {
        byte[] buf = new byte[64]; // line length
        int cnt = 0, c;
        while ((c = read()) != -1)
        {
            if (c == '\n')
                break;
            buf[cnt++] = (byte) c;
        }
        return new String(buf, 0, cnt);
    }

    public int nextInt() throws IOException
    {
        int ret = 0;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();
        do
        {
            ret = ret * 10 + c - '0';
        }  while ((c = read()) >= '0' && c <= '9');

        if (neg)
            return -ret;
        return ret;
    }

    public long nextLong() throws IOException
    {
        long ret = 0;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();
        do {
            ret = ret * 10 + c - '0';
        }
        while ((c = read()) >= '0' && c <= '9');
        if (neg)
            return -ret;
        return ret;
    }

    public double nextDouble() throws IOException
    {
        double ret = 0, div = 1;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();

        do {
            ret = ret * 10 + c - '0';
        }
        while ((c = read()) >= '0' && c <= '9');

        if (c == '.')
        {
            while ((c = read()) >= '0' && c <= '9')
            {
                ret += (c - '0') / (div *= 10);
            }
        }

        if (neg)
            return -ret;
        return ret;
    }

    private void fillBuffer() throws IOException
    {
        bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
        if (bytesRead == -1)
            buffer[0] = -1;
    }

    private byte read() throws IOException
    {
        if (bufferPointer == bytesRead)
            fillBuffer();
        return buffer[bufferPointer++];
    }

    public void close() throws IOException
    {
        if (din == null)
            return;
        din.close();
    }
}
class SegmentTree
{
    public int nextPowerOfTwo(int num)
    {
        if(num == 0)
            return 1;
        if(num > 0 && (num & (num - 1)) == 0)
            return num;
        while((num &(num - 1)) > 0)
        {
            num = num & (num - 1);
        }
        return num << 1;
    }

}
class FenwickTree
{
    public void update(long[] fenwickTree,long delta,int index)
    {
        index += 1;
        while(index < fenwickTree.length)
        {
            fenwickTree[index] += delta;
            index = index + (index & (-index));
        }
    }
    public long prefixSum(long[] fenwickTree,int index)
    {
        long sum = 0L;
        index += 1;
        while(index > 0)
        {
            sum += fenwickTree[index];
            index -= (index & (-index));
        }
        return sum;
    }
}
class SegmentTree1
{
    public int nextPowerOfTwo(int num)
    {
        if(num == 0)
            return 1;
        if(num > 0 && (num & (num - 1)) == 0)
            return num;
        while((num &(num - 1)) > 0)
        {
            num = num & (num - 1);
        }
        return num << 1;
    }
    public int[] createSegmentTree(int[] input)
    {
        int np2 = nextPowerOfTwo(input.length);
        int[] segmentTree = new int[np2 * 2 - 1];

        for(int i=0;i<segmentTree.length;i++)
            segmentTree[i] = Integer.MAX_VALUE;

        constructSegmentTree(segmentTree,input,0,input.length-1,0);
        return segmentTree;

    }
    private void constructSegmentTree(int[] segmentTree,int[] input,int low,int high,int pos)
    {
        if(low == high)
        {
            segmentTree[pos] = input[low];
            return;
        }
        int mid = (low + high)/ 2;
        constructSegmentTree(segmentTree,input,low,mid,2*pos + 1);
        constructSegmentTree(segmentTree,input,mid+1,high,2*pos + 2);
        segmentTree[pos] = Math.min(segmentTree[2*pos + 1],segmentTree[2*pos + 2]);
    }
    public int rangeMinimumQuery(int[] segmentTree,int qlow,int qhigh,int len)
    {
        return rangeMinimumQuery(segmentTree,0,len - 1,qlow,qhigh,0);
    }
    private int rangeMinimumQuery(int[] segmentTree,int low,int high,int qlow,int qhigh,int pos)
    {
        if(qlow <= low && qhigh >= high)
        {
            return segmentTree[pos];
        }
        else if(qlow > high || qhigh < low)
        {
            return Integer.MAX_VALUE;
        }
        int mid = (low + high)/2;
        return Math.min(rangeMinimumQuery(segmentTree,low,mid,qlow,qhigh,2*pos+1),rangeMinimumQuery(segmentTree,mid+1,high,qlow,qhigh,2*pos+2));
    }
    public void updateSegmentTreeRangeLazy(int[] input,int[] segmentTree,int[] lazy,int startRange,int endRange,int delta)
    {
        updateSegmentTreeRangeLazy(input,segmentTree,lazy,startRange,endRange,delta,0,input.length-1,0);
    }
    private void updateSegmentTreeRangeLazy(int[] input,int[] segmentTree,int[] lazy,int startRange,int endRange,int delta,int low,int high,int pos)
    {
        if(low > high)
        {
            return;
        }
        if(lazy[pos] != 0)
        {
            segmentTree[pos] += lazy[pos];
            if(low != high)
            {
                lazy[2*pos+1] += lazy[pos];
                lazy[2*pos + 2] += lazy[pos];
            }
            lazy[pos] = 0;
        }
        if(startRange > high || endRange < low)
            return;
        if(startRange <= low && endRange >= high)
        {
            segmentTree[pos] += delta;
            if(low != high)
            {
                lazy[2*pos + 1] += delta;
                lazy[2*pos + 2] += delta;
            }
            return;
        }
        int mid = (low + high)/2;
        updateSegmentTreeRangeLazy(input,segmentTree,lazy,startRange,endRange,delta,low,mid,2*pos + 1);
        updateSegmentTreeRangeLazy(input,segmentTree,lazy,startRange,endRange,delta,mid + 1,high,2 * pos + 2);
        segmentTree[pos] += Math.min(segmentTree[2*pos + 1],segmentTree[2*pos + 2]);
    }
    public int rangeMinimumQueryLazy(int[] segmentTree,int[] lazy,int qlow,int qhigh,int len)
    {
        return rangeMinimumQueryLazy(segmentTree,lazy,qlow,qhigh,0,len - 1,0);
    }
    private int rangeMinimumQueryLazy(int[] segmentTree,int[] lazy,int qlow,int qhigh,int low,int high,int pos)
    {
        if(low > high)
            return Integer.MAX_VALUE;
        if(lazy[pos] != 0)
        {
            segmentTree[pos] += lazy[pos];
            if(low != high)
            {
                lazy[2*pos + 1] += lazy[pos];
                lazy[2*pos + 2] += lazy[pos];
            }
            lazy[pos] = 0;
        }
        if(qlow > high || qhigh < low)
            return Integer.MAX_VALUE;
        if(qlow <= low && qhigh >= low)
            return segmentTree[pos];
        int mid = (low + high)/2;
        return Math.min(rangeMinimumQueryLazy(segmentTree,lazy,qlow,qhigh,low,mid,2*pos + 1),rangeMinimumQueryLazy(segmentTree,lazy,qlow,qhigh,mid + 1,high,2*pos + 2));
    }
}