#include <iostream>
using namespace std;
int main ()
{
int S, n, A[1005], i, a, b;
S=a=b=0;
cin>> n;
for ( i=1; i<=n; i++)
cin>> A[i];
for ( i=1; i<=n; i++)
{
if(A[i]%2==0)
a=i;
}
for( i=n; i>=1; i--)
{
if( A[i]%2== 0)
b=i;
}
for (i=b; i<=a; i++)
S= S+ A[i];
if(a!=b)
cout<< S;
else
cout<< "NU EXISTA";
return 0;
}