#include<iostream>

using namespace std;

int main(){
    int n; cin >> n;
    int arr[n];
    int sum = 0;
    for(int i=0; i<n; ++i){
        cin >> arr[i];
        sum += arr[i];
    }
    for(int i=0; i<n; ++i){
        if(sum - arr[i] == arr[i]){
            cout << arr[i];
            break;
        }
    }
    cout << "BAD";
}