#include <bits/stdc++.h>
using namespace std;
#define rep(i,l,r) for(int i=(l);i<(r);++i)
typedef long long ll;

int main(){
	int d,a,b; cin>>d>>a>>b;
	double x=b/(a+b)*d;
	cout<<a*x+(d-x)*b<<endl;
}