func_code_string: #include <bits/stdc++.h>   using namespace std;   int lpd(int n) {     int ans = -1;     for (int i = 2; i * i <= n; i++) {       if (n % i == 0) {         ans = i;         while (n % i == 0) n /= i;       }     }     if (n > 1) ans = n;     return ans;   }   int x, p[1000006], pd, t, ans;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     p[0] = p[1] = 1;     for (int i = 2; i * i <= 1e6; i++) {       if (p[i] == 0) {         for (int j = i * i; j <= 1e6; j += i) {           p[j] = 1;         }       }     }     cin >> x;     ans = 1e9;     pd = lpd(x);     t = x / pd;     t -= 1;     if (p[pd * t + 1] == 0 && (pd * t + 2 == x)) {       cout << (x - 1) <<   n ;       return 0;     }     for (int i = pd * t + 1; i < x; i++) {       if (p[i] == 0) continue;       pd = lpd(i);       t = i / pd;       t -= 1;       ans = min(ans, pd * t + 1);     }     cout << ans <<   n ;   }   