#include <bits/stdc++.h>
using namespace std;

int n;
const int fin = 3000;
double p, q;
int visited[5010][1010][2] = {};
double memo[5010][1010][2];

double dp(int i, int num, int si){
    if(i == fin) return 0;
    if(num < 0) return 1;
    if(num == n) return 0;
    if(visited[i][num][si] == 1) return memo[i][num][si];

    visited[i][num][si] = 1;
    if(si == 1){
        return memo[i][num][si] = dp(i+1, num-1, 0)*p+dp(i+1, num+1, si)*q;
    }else{
        return memo[i][num][si] = dp(i+1, num-1, si)*q+dp(i+1, num+1, 1)*p;
    }
}

int main(){
    cin >> n;
    cin >> p >> q;

    printf("%.12lf\n", dp(0, 0, 1));
    return 0;
}