#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};
/*-------------------------------------------------*/
int n;
double ans = 0, p, q;
void calc(int pos, bool right, double now) {
  if (now < EPS) return;
  if (right) {
    if (pos == 1) {
      ans += now * p;
      calc(pos + 1, true, now * q);
    } else if (pos == n) {
      calc(pos - 1, false, now * p);
    } else {
      calc(pos - 1, false, now * p);
      calc(pos + 1, true, now * q);
    }
  } else {
    if (pos == 1) {
      ans += now * q;
      calc(pos + 1, true, now * p);
    } else if (pos == n) {
      calc(pos - 1, false, now * q);
    } else {
      calc(pos - 1, false, now * q);
      calc(pos + 1, true, now * p);
    }
  }
}

int main() {
  cin.tie(0); ios::sync_with_stdio(false);
  // freopen("input.txt", "r", stdin);

  cin >> n >> p >> q;
  calc(1, true, 1);
  printf("%.7f\n", ans);
  return 0;
}