#include <bits/stdc++.h>
#define endl '\n'
using namespace std;

double a, b, c, ans;

int main()
{
    freopen("competition.in", "r", stdin);
    freopen("competition.out", "w", stdout);

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin>>a>>b>>c;
    ans = 0.05 * a + 0.1 * b + 0.15 * c;

    if(ans >= 6) cout<<"6.00"<<endl;
    else if(ans <= 2.99) cout<<"2.00"<<endl;
    else cout<<fixed<<setprecision(2)<<ans<<endl;

    return 0;
}