#include <bits/stdc++.h>
using namespace std;

signed main(){
  int N; cin >> N;
  vector< double > A( N );
  for( int i = 0; i < N; ++i )
    cin >> A[ i ];
  double sum = 0.0;
  for( int i = 0; i < N; ++i )
    sum += A[ i ];
  cout << fixed << setprecision( 10 ) << sum << endl;
  return 0;
}