#include <bits/stdc++.h>
using namespace std;
#define incID(i, l, r) for(int i = (l)    ; i <  (r); ++i)
#define inc(i, n)  incID(i, 0, n)

// ---- ----

int main() {
	int n;
	double p, q, r;
	cin >> n >> p >> q;
	
	r = 0;
	inc(i, n) { r = p + q * q * r / (1 - p * r); }
	
	printf("%.6f\n", r);
	
	return 0;
}