题解

#include <bits/stdc++.h>
using namespace std;
int main(){
    int n ;
	double sum = 0 ,j;
    cin >> n;
    for (int i = 1 ; i <= n ; i++){
    	cin >> j;
    	sum += j;
	}
	printf("%.1f" ,sum * 10);
    return 0;
}