#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = uint32_t;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    int n;
    double p, q;
    cin >> n >> p >> q;
    if(p == 1){
        puts("1");
        return 0;
    }
    double p1 = 0, q1 = 1, p2 = p, q2 = q;
    while (n > 0){
        if (n&1) {
            double pp = p1+q1*q1*p2/(1-p1*p2);
            double qq = q1*q2/(1-p1*p2);
            p1 = pp, q1 = qq;
        }
        double pp = p2+q2*q2*p2/(1-p2*p2);
        double qq = q2*q2/(1-p2*p2);
        p2 = pp, q2 = qq;
        n >>= 1;
    }
    printf("%.15lf\n", p1);
    return 0;
}