#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;
}

/*================================*/
#if DEBUG
#define SIZE 1230
#else
#define SIZE 1230
#endif

int N;
double p,q;
// i回目の逃走でj番目の門で折り返す場合の確率
double DP[1010][SIZE];

void solve() {
    cin>>N>>p>>q;
    
    int I=min(1e3, 5e5/N);
    REP1(j,N) {
        DP[0][j] = pow(q, j-1) * p;
    }
    REP1(i,I)REP1(j,N) {
        double base = p;
        RREP1(k,j-1) {
            if (i%2) {
                DP[i][k] += DP[i-1][j] * base;
            } else {
                DP[i][j] += DP[i-1][k] * base;
            }
            base *= q;
        }
        if (i%2) {
            DP[i][0] += DP[i-1][j] * base / p;
        }
    }
    double ans = 0;
    REP1(i,I) ans += DP[i][0];
    out("%.14f\n", ans);
}