#include<iostream>
#include<vector>
#include<iomanip>

int main() {
  int n;
  double p, q;
  std::cin >> n >> p >> q;
  if (p == 1) {
    std::cout << "1\n";
    return 0;
  }
  std::vector<double> dp0(n + 1), dp1(n + 1);
  dp0[0] = 0;
  dp1[0] = 1;
  for (int i = 1; i != n + 1; i += 1) {
    dp1[i] = dp1[i - 1] * q / (1 - p * dp0[i - 1]);
    dp0[i] = dp0[i - 1] + dp1[i - 1] * p * dp1[i - 1] / (1 - p * dp0[i - 1]);
  }
  std::cout << std::setprecision(20) << dp0[n] << "\n";
}