#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; double money=0; int n,a[1501],c=0; int main(){ cin>>n; for(int i=1;i<=n;i++) cin>>a[i]; for(int i=1;i<=n;i++){ if(a[i]>70) c=c+a[i]/70; } money=0.1*n+0.1*c; printf("%.1lf",money); return 0; }