#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    cin>>n;
    int a=0;
    int m;
    for(int i=1;i<=n;i++){
        cin>>m;
        if(m%2==0){
            a=a+m;
        }
    }
    cout<<a;
    return 0;
}

C :

#include <stdio.h>

int main() {
    int n;
    scanf("%d", &n);
    int sum = 0, num;
    while (n --) {
        scanf("%d", &num);
        if (!(num % 2)) {
            sum += num;
        }
    }
    printf("%d\n", sum);
    return 0;
}

C++ :

#include <stdio.h>
int a[100000];
int main()
{
	int n;
	while(scanf("%d",&n)!=EOF)
	{
		long long sum=0;
		for(int i=0;i<n;i++)
		{
			scanf("%d",&a[i]);
			if(a[i]%2==0)
			sum+=a[i];
		}
		printf("%lld\n",sum);
	}
	return 0;
}