#include <iostream>
#include <cstdio>
#include <string>
#include <string>
#include <algorithm>
#include <cstdlib>
using namespace std;

typedef long long ll;

int a[50];
ll c[50][50];
int main(void) {
    c[0][0] = 1;
    for (int i = 1; i <= 30; ++ i) {
        c[i][0] = c[i][i] = 1;
        for (int j = 1; j < i; ++ j) {
            c[i][j] = c[i - 1][j - 1] + c[i - 1][j];
        }
    }

    int T, cas = 1;
    scanf("%d", &T);
    while (T -- > 0) {
        int ans = 0;
        int n;
        scanf("%d", &n);
        for (int i = 0; i < n; ++ i) {
            scanf("%d", a + i);
            ans = max(ans, a[i]);
        }
        /*
        sort(a, a + n);

        for (int i = 0; i < n; ++ i) {
            int left = n - i - 1;
            for (int j = 0; j <= left; j += 2) {
                ans += (c[left][j] - c[left][j + 1]) * a[i];
            }
        }
        */

        printf("%d\n", ans);


    }

    return 0;
}