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.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.HashSet;
import java.util.Set;
import java.util.StringTokenizer;
 
 
public class Solution{
    
    ///////////////////////////////////////////////////////////////////////////
    static class FastScanner{
        BufferedReader s;
        StringTokenizer st;
        
        public FastScanner(InputStream InputStream){
            st = new StringTokenizer("");
            s = new BufferedReader(new InputStreamReader(InputStream));
        }
        
        public FastScanner(File f) throws FileNotFoundException{
            st = new StringTokenizer("");
            s = new BufferedReader (new FileReader(f));
        }
        
        public int nextInt() throws IOException{
            if(st.hasMoreTokens())
                return Integer.parseInt(st.nextToken());
            else{
                st = new StringTokenizer(s.readLine());
                return nextInt();
            }
        }
        
        public BigInteger big() throws IOException{
            if(st.hasMoreTokens())
                return new BigInteger(st.nextToken());
            else{
                st = new StringTokenizer(s.readLine());
                return big();
            }
        }
        
        public double nextDouble() throws IOException{
            if(st.hasMoreTokens())
                return Double.parseDouble(st.nextToken());
            else{
                st = new StringTokenizer(s.readLine());
                return nextDouble();
            }
        }
      
        public long nextLong() throws IOException{
            if(st.hasMoreTokens())
                return Long.parseLong(st.nextToken());
            else{
                st = new StringTokenizer(s.readLine());
                return nextLong();
            }
        }
        
        public String nextString() throws IOException{
            if(st.hasMoreTokens())
                return st.nextToken();
            else{
                st = new StringTokenizer(s.readLine());
                return nextString();
            }
            
        }
        public String readLine() throws IOException{
            return s.readLine();
        }
        
        public void close() throws IOException{
            s.close();
        }
        
    }
    
    ////////////////////////////////////////////////////////////////////
    //      Number Theory
    
    long pow(long a,long b,long mod){
        long x = 1; long y = a;
        while(b > 0){
            if(b % 2 == 1){
                x = (x*y);
                x %= mod;
            }
            y = (y*y);
            y %= mod;
            b /= 2;         
        }
        return x;
    }
    
    int divisor(long x,long[] a){
        long limit = x;
        int numberOfDivisors = 0;
 
        for (int i=1; i < limit; ++i) {
            if (x % i == 0) {
                limit = x / i;
                if (limit != i) {
                    numberOfDivisors++;
                }
                numberOfDivisors++;
            }
        }
        return numberOfDivisors;
    }
    
    void findSubsets(int array[]){
        long numOfSubsets = 1 << array.length; 
        for(int i = 0; i < numOfSubsets; i++){    
            @SuppressWarnings("unused")
            int pos = array.length - 1;
            int bitmask = i;
            while(bitmask > 0){     
                if((bitmask & 1) == 1)
//                    ww.print(array[pos]+" ");
                bitmask >>= 1;
                pos--;
            }
//            ww.println();
        }
    }
    
    
    public static long gcd(long a, long b){
        return b == 0 ? a : gcd(b,a%b);
    }
    
  
    public static int lcm(int a,int b, int c){
        return lcm(lcm(a,b),c);
    }
    
    public static int lcm(int a, int b){
        return (int) (a*b/gcd(a,b));
    }
    
    public static long invl(long a, long mod) {
        long b = mod;
        long p = 1, q = 0;
        while (b > 0) {
            long c = a / b;
            long d;
            d = a;
            a = b;
            b = d % b;
            d = p;
            p = q;
            q = d - c * q;
        }
        return p < 0 ? p + mod : p;
    }
    
    ////////////////////////////////////////////////////////////////////
    
    
//    FastScanner s = new FastScanner(new File("input.txt"));
//    PrintWriter ww = new PrintWriter(new FileWriter("output.txt"));
    static InputStream inputStream = System.in;
    static FastScanner s = new FastScanner(inputStream); 
    static OutputStream outputStream = System.out;
    static PrintWriter ww = new PrintWriter(new OutputStreamWriter(outputStream));
//      private static Scanner s = new Scanner(System.in);
    @SuppressWarnings("unused")
    private static int[][] states = { {-1,0} , {1,0} , {0,-1} , {0,1} };
    
      
    //////////////////////////////////////////////////////////////////// 
     
    
     
    public static void main(String[] args) throws IOException{
        new Solution().solve();
        s.close();
        ww.close();
    }
    
    
    ////////////////////////////////////////////////////////////////////
    
    int n;
    int ans = 0;
    
    void f(String num){
        
        
        if(!num.equals("")){
            if(Long.parseLong(num) > n || num.length() > Integer.toString(n).length() || (num.charAt(0) == '0')) return;
 //         System.out.println(num);
                 ans++; 
        }
        
        for(int i=0;i<=9;i++){
            String xx = num+Integer.toString(i);
            Set<Character> st = new HashSet<Character>();
            for(int j=0;j<xx.length();j++) st.add(xx.charAt(j));
            if(st.size() == 1 || st.size() == 2) f(xx);
        }
        
    }
    
    void solve() throws IOException{
       
        n = s.nextInt();
        f("");
        ww.println(ans);
    }
}





