复赛一：成绩(score)

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#include<bits/stdc++.h>
using namespace std;
int main(){	
    freopen("score.in","r",stdin);
    freopen("score.out","w",stdout);
    int a,b,c;
	cin>>a>>b>>c;
	cout<<a*0.2+b*0.3+c*0.5;
	return 0;
}