#include <bits/stdc++.h>
using namespace std;
using lint = long long;
template<class T = int> using V = vector<T>;
template<class T = int> using VV = V< V<T> >;

int main() {
  cin.tie(nullptr); ios::sync_with_stdio(false);
  int n; cin >> n;
  double p, q; cin >> p >> q;
  V<double> r(n + 1);
  for (int i = 0; i < n; ++i) {
    r[i + 1] = p + q * q * r[i] / (1 - p * r[i]);
  }
  cout << fixed << setprecision(15) << r[n] << '\n';
}