func_code_string: #include <bits/stdc++.h>   using ll = long long;   using namespace std;   int main() {     cin.tie(0);     cin.sync_with_stdio(0);     int n, r;     cin >> n >> r;     double R = -r / (sin(acos(-1) / n) - 1);     double ans = R - r;     cout << fixed << setprecision(10) << ans;   }   