T1

題面傳送門

直接模擬，不多說了，官方也沒有卡精度，考察你會不會程式設計

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>
#define rep(i,a,b) for(int i=a;i<=b;i++)
#define dep(i,a,b) for(int i=a;i>=b;i--)
#define ll long long
#define mem(x,num) memset(x,num,sizeof x)
 

#ifdef WIN32
#define LL "%I64d"
#else 
#define LL "%lld"
#endif
using namespace std;
inline ll read()
{
    ll f=1,x=0;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}

int main()
{
    int
 
 a,b,c;
    cin>>a>>b>>c;
    cout<<a*0.2+b*0.3+c*0.5<<endl;
    return 0;
}