func_code_string: #include <bits/stdc++.h>   using namespace std;   bool f(int a, string s) {     vector<char> v;     int tmp;     int ss = (s.size() - 1);     while (a) {       tmp = a % 10;       if (tmp == 7) v.push_back( 7 );       if (tmp == 4) v.push_back( 4 );       a /= 10;     }     if (v.size() != s.size()) return false;     for (int i = 0; i < s.size(); i++) {       if (s[i] != v[s.size() - i - 1]) return false;     }     return true;   }   int main() {     int a;     string s;     cin >> a >> s;     for (int i = (a + 1); i <= 100000000; i++) {       if (f(i, s)) {         cout << i << endl;         return 0;       }     }   }   