func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAX = 1e6 + 10;   const int INF = 1e9 + 7;   int prime[MAX];   int main() {     int x2;     scanf( %d , &x2);     for (int i = 2; i <= x2; i++) {       if (!prime[i]) {         for (int j = i * 2; j <= x2; j += i) prime[j] = i;       }     }     int ans = INF;     for (int i = x2 - prime[x2] + 1; i <= x2; i++) {       if (prime[i] == 0) continue;       ans = min(ans, i - prime[i] + 1);     }     printf( %d n , ans);     return 0;   }   