#include<bits/stdc++.h>
using namespace std;
int main(){
    double a,b,c;
    double p;
    cin>>a>>b>>c;
    p=(a+b+c)*1/2.0;
    cout<<sqrt(p*(p-a)*(p-b)*(p-c));
    cout<<fixed<<setprecision(1)<<sum;
    return 0;
}