#include <bits/stdc++.h>

using namespace std;

typedef __float128 flt;

int main(void)
{
  int n;
  flt res;
  long double a;
  res = 0;
  scanf("%d",&n);
  for( int i = 0; i < n; i++ ) {
    cin >> a;
    res += a;
  }
  printf("%.10Lf\n",(long double)res);
  return 0;
}