#include<bits/stdc++.h>
using namespace std;
int n,a[10000005];
double ans=0;
int main() {
	cin>>n;
    for(int i=1;i<=n;++i){
        cin>>a[i];
    	ans+=ceil(a[i]*1.0/70)*0.1;
	}
	cout<<ans;
    return 0;
}