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

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

        int score = 0;
        score += pos / 3;
        pos %= 3;

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

        score += neg / 3;
        neg %= 3;

        if ((pos > 0) || (neg > 0 && neg != 3)) {
            printf("0\n");
        } else {
            printf("%d\n", score);
        }
    }
    return 0;
}