func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     double x, cx;     cin >> n >> x;     cx = x;     double a[n + 1], b[n + 1];     for (int i = 1; i <= n; i++) {       cin >> a[i];       if (a[i] == 1) {         cout << -1;         return 0;       }     }     for (int i = 1; i <= n; i++) {       cin >> b[i];       if (b[i] == 1) {         cout << -1;         return 0;       }     }     x = x + x / (b[1] - 1);     for (int i = n; i > 1; i--) {       x = x * a[i] / (a[i] - 1);       x = x * b[i] / (b[i] - 1);     }     x = x + x / (a[1] - 1);     cout << setprecision(8) << x - cx;     return 0;   }   