func_code_string: #include <bits/stdc++.h>   using namespace std;   int prime[1000100];   void get_prime() {     for (int i = 2; i < 1000100; i++) {       if (!prime[i]) {         for (int j = i * 2; j < 1000100; j += i) {           prime[j] = i;         }       }     }     for (int i = 2; i < 1000100; i++) {       if (!prime[i]) {         prime[i] = 1;       }     }   }   int main() {     get_prime();     int x2;     cin >> x2;     int ans = 0x3f3f3f3f3f;     for (int i = x2 - prime[x2] + 1; i <= x2; i++) {       ans = min(ans, i - prime[i] + 1);     }     cout << ans;   }   