cf #327 Div.2 Problem A Wizards' Duel

#include <iostream>
#include <cstdio>
using namespace std;
int main()
{
    int l,p,q;
    scanf("%d%d%d",&l,&p,&q);
    double ans;
    ans=(double)l*1.0/(p+q)*p;
    printf("%lf\n",ans);
    return 0;
}