#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <map>
#include <cstring>

using namespace std;

int N;
double P, Q;
double dp[1010];

int main() {
  cin >> N >> P >> Q;
  if (N == 1) {
    printf("%.15f\n", P);
    return 0;
  }
  dp[N] = Q;
  for (int i = N - 1; i >= 0; i--) {
    dp[i] = P + Q * dp[i+1] * Q / (1 - dp[i+1]*P);
  }
  printf("%.15f\n", dp[0]);
}