#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <chrono>
#define _USE_MATH_DEFINES
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;

#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

const int INF = 0x3f3f3f3f;
const long long LINF = 0x3f3f3f3f3f3f3f3fLL;
const double EPS = 1e-8;
const int MOD = 1000000007; // 998244353;
const int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
/*-------------------------------------------------*/
double p, q;
void calc(double &ans_p, double &ans_q) {
  double p_1 = ans_p, q_1 = ans_q, bunbo = 1 - p_1 * p;
  ans_p += p * q_1 * q_1 / bunbo;
  ans_q = q_1 * q / bunbo;
}

int main() {
  // freopen("input.txt", "r", stdin);

  int n; cin >> n >> p >> q;
  double ans_p = p, ans_q = q;
  while (--n) {
    calc(ans_p, ans_q);
  }
  printf("%.5f\n", ans_p);
}