#491 Suma2

#include <iostream>

using namespace std;

int a[1001];

int main()

{

   int n, i, p=-1, u=-1, s=0;

   cin >> n;

   for (i=1; i<=n; ++i)

   {

      cin >> a[i];

      if (a[i]%2==0)

          {

              if (p==-1) {p=i; u=i;}

              if (p!=-1) u=i;

          }

   }

   if (p==-1) cout << "NU EXISTA";

   else

   {

       for (i=p; i<=u; ++i) s+=a[i];

       cout << s;

   }

   return 0;

}