func_code_string: #include <bits/stdc++.h>   using namespace std;   using namespace std;   vector<bool> Prime(20000000 + 1, 1);   vector<bool> Pal(20000000 + 1, 1);   void gen1() {     long long int n = 2000000;     Prime[1] = 0;     for (long long int i = 2; i <= 20000000; i++) {       if (Prime[i]) {         for (long long int j = i + i; j <= n; j += i) Prime[j] = false;       }     }   }   void gen2() {     long long int n = 20000000;     long long int num, rev = 0, digit;     for (long long int i = 1; i <= 20000000; i++) {       num = i;       while (num > 0) {         digit = num % 10;         rev = rev * 10 + digit;         num = num / 10;       }       if (i != rev) Pal[i] = false;       rev = 0;     }   }   long long int a, b;   int main() {     ios::sync_with_stdio(false);     gen1(), gen2();     cin >> a >> b;     long long int ans = 1, primes = 0, pals = 0;     for (long long int i = 1; i <= 20000000; i++) {       if (Prime[i]) primes++;       if (Pal[i]) pals++;       if (b * primes <= a * pals) ans = max(ans, i);     }     cout << ans;   }   