func_code_string: #include <bits/stdc++.h>   using namespace std;   bool si[1000007];   int x0 = 1000007;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int x2;     cin >> x2;     si[0] = si[1] = false;     for (int i = 2; i < 1000007; i++) {       si[i] = true;     }     for (int i = 2; i < 1000007; i++) {       if (si[i]) {         for (int j = i * 2; j < 1000007; j += i) {           si[j] = false;         }       }     }     int lp = 0;     for (int i = 2; i <= sqrt(x2); i++) {       if (x2 % i == 0) {         if (si[i]) lp = max(lp, i);         if (si[x2 / i]) lp = max(lp, x2 / i);       }     }     for (int x1 = (x2 / lp - 1) * lp + 1; x1 <= x2; x1++) {       for (int i = 2; i <= sqrt(x1); i++) {         if (x1 % i == 0) {           if (si[i]) {             if (((x1 / i - 1) * i + 1) >= 3) x0 = min(x0, (x1 / i - 1) * i + 1);           }           if (si[x1 / i]) {             if (((i - 1) * (x1 / i) + 1) >= 3)               x0 = min(x0, (i - 1) * (x1 / i) + 1);           }         }       }     }     cout << x0;   }   