/* -*- coding: utf-8 -*-
 *
 * 813.cc:  No.813 ユキちゃんの冒険 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

typedef long double ld;

/* global variables */

/* subroutines */

/* main */

int main() {
  int n;
  ld p, q;
  scanf("%d%Lf%Lf", &n, &p, &q);

  if (p == 1.0) {
    puts("1");
    return 0;
  }

  ld p1 = p, q1 = q, &p2 = p, &q2 = q;
  for (int i = 1; i < n; i++) {
    ld d = 1.0 / (1.0 - p1 * p2);
    ld pp = p1 + p2 * q1 * q1 * d;
    ld qq = q1 * q2 * d;
    p1 = pp, q1 = qq;
  }

  printf("%.17Lf\n", p1);
  return 0;
}