#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0;i<((int)(n));i++)
#define reg(i,a,b) for(int i = ((int)(a));i<=((int)(b));i++)
#define irep(i,n) for(int i = ((int)(n)-1);i>=0;i--)
#define ireg(i,a,b) for(int i = ((int)(b));i>=((int)(a));i--)
typedef long long ll;

/*
AC
*/

struct D{double p,q;};
ll n;
double p,q;

//門の合成
D cross_gate(D g1,D g2){
	return {g1.p+(g1.q*g1.q*g2.p)/(1-g1.p*g2.p), g1.q*g2.q/(1-g1.p*g2.p)};
}

//バイナリ法
D modpow(D g,ll n){
	if(g.p==1)return {1,0};
	D g0={0,1};
	while(n){
		if(n%2==1)g0=cross_gate(g,g);
		g = cross_gate(g,g);
		n>>=1;
	}
	return g;
}

void init(){
	cin>>n>>p>>q;
}

int main(void){
	init();
	D g = modpow({p,q},n);
	cout<<fixed<<setprecision(15)<<g.p<<endl;
	return 0;
}