func_code_string: #include <bits/stdc++.h>   using namespace std;   const int INF = 0x7fffffff;   inline int reint() {     int d;     scanf( %d , &d);     return d;   }   inline long relong() {     long l;     scanf( %ld , &l);     return l;   }   inline char rechar() {     scanf(   );     return getchar();   }   inline double redouble() {     double d;     scanf( %lf , &d);     return d;   }   inline string restring() {     string s;     cin >> s;     return s;   }   int mask(int a) {     char str[10];     sprintf(str,  %d , a);     char ans[10];     int j = 0;     for (int i = (0); i < (strlen(str)); i++) {       if (str[i] ==  4  || str[i] ==  7 ) {         ans[j++] = str[i];       }     }     int res = 0;     for (int i = (0); i < (j); i++) {       res += ans[i] -  0 ;       if (i != j - 1) {         res *= 10;       }     }     return res;   }   int c, b;   int main(void) {     cin >> c >> b;     c++;     while (mask(c) != b) {       c++;     }     cout << c << endl;     return 0;   }   