func_code_string: #include <bits/stdc++.h>   using namespace std;   long long fac(long long n) {     long long m = 1;     for (long long i = 1; i <= n; i++) {       m = m * i;     }     return m;   }   long long gcd(long long x, long long y) {     if (x > y) swap(x, y);     long long md;     while (1) {       md = y % x;       if (md == 0) break;       y = x;       x = md;     }     return x;   }   long long nCr(long long n, long long r) {     long long rs = (fac(n)) / (fac(r) * fac(n - r));     return rs;   }   long long nPr(long long n, long long r) {     long long rs = fac(n) / fac(n - r);     return rs;   }   bool flag, fl;   long long i, j;   long long pw(long long n, long long p) {     long long mn = 1;     if (p == 0) return 1;     for (long long z = 0; z < p; z++) {       mn *= n;     }     return mn;   }   int main() {     long long n;     scanf( %lld , &n);     long long num = 0;     vector<int> bn;     long long rsl;     for (i = 1; i <= 1024; i++) {       bn.clear();       j = i;       num = 0;       while (j > 0) {         bn.push_back(j % 2);         j = j / 2;       }       long long ln = bn.size();       for (j = 0; j < ln; j++) {         num += (bn[j] * pw(10, j));       }       if (num <= n) {         rsl = i;       } else         break;     }     printf( %lld n , rsl);     return 0;   }   