#include<bits/stdc++.h>
#define MOD 1000000007
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3f
#define EPS (1e-10)
#define rep(i,n)for(int i=0;i<n;i++)
using namespace std;
typedef long long ll;
typedef pair<int, int>P;

int main() {
	int n; scanf("%d", &n);
	long double sum = 0;
	rep(i, n) {
		long double d; scanf("%llf", &d);
		sum += d;
	}
	printf("%.10llf\n", sum);
}