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

using namespace std;

int N;
double P, Q;
double dp0[1000][2];
double dp1[1000][2];

int main() {
  cin >> N >> P >> Q;
  dp0[0][0] = 1;
  double ans = 0;
  for (int ii = 0; ii < 5000; ii++) {
    memset(dp1, 0, sizeof(dp1));
    for (int i = 0; i + 1 < N; i++) {
      dp1[i + 1][0] += dp0[i][0] * Q;
    }
    for (int i = 0; i + 1 < N; i++) {
      dp1[i][1] += dp0[i + 1][1] * Q;
    }
    for (int i = 0; i < N; i++) {
      dp1[i][1] += dp0[i][0] * P;
    }
    for (int i = 1; i < N; i++) {
      dp1[i][0] += dp0[i][1] * P;
    }
    swap(dp0, dp1);
    ans += dp0[0][1];
  }
  printf("%.15f\n", ans);
}