#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int l(int x){ int sum=0; if(x<=70) sum++; else{ if(x%70==0)sum+=x/70; else sum+=x%70+1; } return sum; } int main(){ int n,a[101]={}; float s=0; cin>>n; for(int i=1;i<=n;i++){ cin>>a[i]; s+=l(a[i]); } cout<<s*0.1<<endl; return 0; }