#include<bits/stdc++.h>
using namespace std;
int n;
int a[10005];
int s=0;
int main(){
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a[i];
		s+=a[i]/70+1;
		if(a[i]%70==0) s--;
		//如果字数是70倍数就会多加一个 
	}
	cout<<s*0.1<<"\n";
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int n,ioi,num,numb;
double sum;
int main(){
   cin>>n;
   for(int i=0;i<n;i++){
      cin>>ioi;
      if(ioi<=70){
         sum+=0.1;}
      else if(ioi>70){
         num=ioi/70;
         sum+=num*0.1;
         numb=ioi%70;
         if(numb>0){
            sum+=0.1;}}}
   cout<<sum;
   return 0;
}