#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
#include <memory>
#include <regex>
using namespace std;

const double EPS = 1.0e-10;

double solve(int n, double p1, double q1)
{
    if(p1 >= 1.0 - EPS)
        return 1.0;

    double p = p1;
    double q = q1;
    while(--n > 0){
        double p2 = q * q * p1 / (1 - p * p1) + p;
        double q2 = q * q1 / (1 - p * p1);
        p = p2;
        q = q2;
    }
    return p;
}

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

    cout.setf(ios_base::fixed, ios_base::floatfield);
    cout << setprecision(10) << solve(n, p, q) << endl;

    return 0;
}