func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     long long n, m, p = 0, q = 0, l = 0, i, flag = 0, k, t, j, r = 0, curr = 0, d;     cin >> n >> m;     long long a[n], b[n];     long double q1 = 1.0000;     for (long long i = 0; i < n; i++) {       cin >> a[i];       q1 *= double(a[i]) / double(a[i] - 1);       if (a[i] == 1) {         flag = 1;       }     }     for (long long i = 0; i < n; i++) {       cin >> b[i];       q1 *= double(b[i]) / double(b[i] - 1);       if (b[i] == 1) {         flag = 1;       }     }     if (flag == 1)       cout << -1 <<   n ;     else {       long double x = q1 * m - m;       if (x < 0)         cout << -1 <<   n ;       else         cout << fixed << setprecision(10) << x <<   n ;     }     return 0;   }   