#include <bits/stdc++.h>
using namespace std;
int main()
{int n,i,x;double cnt=0;cin>>n;for(i=1; i<=n; i++){cin>>x;while(x>0){cnt++;x=x-70;}}printf("%0.1f",cnt*0.1);return 0;
}
#include <bits/stdc++.h>
using namespace std;
int main()
{int n,i,x;double cnt=0;cin>>n;for(i=1; i<=n; i++){cin>>x;while(x>0){cnt++;x=x-70;}}printf("%0.1f",cnt*0.1);return 0;
}