#include <iostream> using namespace std; int sb(int x){ if(x%70==0) return x/70; else return x/70+1; } int main(){ int n,a[1501]; double s=0; cin>>n; for(int i=0;i<n;i++){ cin>>a[i]; s+=sb(a[i]); }printf("%.1lf\n",s/10.0); return 0; }