#include<cstdio>
#include<cstring>
#include<algorithm>
#include<map>
using namespace std;
typedef long long LL;

typedef unsigned long long ULL;

map<ULL, int> mpp;
char s[100];
int n;

void work()
{
    scanf("%d", &n);
    int mx = 0, x;
    for(int i = 1; i <= n; i++) scanf("%d", &x), mx = max(mx, x);
    printf("%d\n", mx);
}

int main()
{
    int _;
    scanf("%d", &_);
    while(_--) work();
    
    return 0;
}