#include "bits/stdc++.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define REP1(i, n) for(int i=1; i<=(n); i++)
#define RREP1(i, n) for(int i=(n); i>=1; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define out(...) printf(__VA_ARGS__)

int dxy[] = {0, 1, 0, -1, 0};

void solve();
signed main()
{
#if DEBUG
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}

/*================================*/
int N;
double p,q;

double calcp(double p1, double q1, double p2, double q2) {
    return p1 + p2*q1*q1 / (1-p1*p2);
}

double calcq(double p1, double q1, double p2, double q2) {
    return q1*q2 / (1-p1*p2);
}

void solve() {
    cin>>N>>p>>q;
    
    double np = p, nq = q;
    REP(i,N-1) {
        double tp = calcp(np, nq, p, q);
        double tq = calcq(np, nq, p, q);
        np = tp;
        nq = tq;
    }
    out("%.14f\n", np);
}