#include <iostream>

using namespace std;

int main()
{
    int allCount;
    cin >> allCount;
    for(int i = 0; i < allCount; i++)
    {
        int length;
        cin >> length;
        int maxNum;
        int temp;
        cin >> maxNum;
        if(length < 2)
        {
            cout << maxNum << endl;
            continue;
        }
        for(int i = 1; i < length; i++)
        {
            cin >> temp;
            if(temp > maxNum)
            {
                maxNum = temp;
            }
        }
        cout << maxNum << endl;
    }
    return 0;
}