#include <bits/stdc++.h>
int m(int a) {
  int ret = 0, i = 1;
  while (a > 0) {
    if (a % 10 == 4 || a % 10 == 7) {
      ret += (i * (a % 10)), i *= 10;
    }
    a /= 10;
  }
  return ret;
}
int main() {
  int a, b;
  while (scanf("%d%d", &a, &b) != EOF) {
    while (1) {
      a++;
      if (m(a) == b) {
        printf("%d\n", a);
        return 0;
      }
    }
  }
}
