#include<stdio.h>
int main()
{
    int t;
    scanf("%d", &t);
    while (t--) {
        int n;
        scanf("%d", &n);

        int pos = 0, neg = 0;
        for (int i = 0; i < n; i++) {
            int ele;
            scanf("%d", &ele);
            if (ele == 1) pos++;
            else if (ele == -1) neg++;
        }

        int sum1 = pos / 3;
        pos %= 3;

        int sub = 0;
        while (pos > 0 && neg >= 2) {
            sub++;
            pos--;
            neg -= 2;
        }

        sub += neg / 3;
        printf("%d\n", sum1 + sub);
    }
    return 0;
}