#include"bits/stdc++.h"

using namespace std;
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

#define FOR(k,m,n) for(ll (k)=(m);(k)<(n);(k)++)
#define REP(i,n) FOR((i),0,(n))
#define WAITING(str) int str;std::cin>>str;
#define DEBUGING(str) cout<< #str << " " str<<endl

constexpr int INF = (1 << 30);
constexpr ll INFL = (1ll << 60);
constexpr ll MOD = 1000000007;// 10^9+7
constexpr int siz = 1e4;
int N;
ld p, q, dead;
vector<vector<ld>> dp;

using namespace chrono;
int main()
{
	auto start = system_clock::now();

	cin >> N >> p >> q;
	dp = vector<vector<ld>>(siz, vector<ld>(N + 2));
	dp[0][1] = 1;

	REP(i, siz - 1) {
		FOR(j, 1, N) {
			dp[i + 1][j - 1] += p * dp[i][j];
			dp[i + 1][j + 1] += q * dp[i][j];
		}
		if (i % 100 == 0) {
			auto now = system_clock::now();
			auto dur = duration_cast<milliseconds>(now - start).count();
			//cerr << dur << endl;
			if (dur > 1800) {
				break;
			}
		}
	}
	ld res = 0;
	REP(i, siz)res += dp[i].front();
	cout << res << endl;
	//cout << "back: " << nowv.front() << "  go:" << nowv.back() << "  dead:" << dead << endl;

	return 0;
}