https://www.acmicpc.net/problem/1546
#include<stdio.h>
int main() {
int n;
scanf("%d",&n);
int sum=0;
int max=0;
for(int i=0;i<n;i++){
int a;
scanf("%d",&a);
if(a>=max) max=a;
sum+=a;
}
printf("%f",(double)sum*100/max/n);
}