#include<iostream>
using namespace std;
int suma( int x[], int i, int j)
{
int v1, v2, s=0;
if(i==j) return x[i];
else
{
v1=suma(x, i, (i+j)/2);
v2=suma(x, (i+j)/2+1,j);
if(v1%2==0 && v2%2==0) return s=v1+v2;
if(v2%2==0) return s=s+v2;
if(v1%2==0) return s=s+v1;
}
}
int main()
{
int a[1002], i, n;
cin>>n;
for(i=1;i<=n;i++) cin>>a[i];
cout<<suma(a,1,n);
return 0;
}
