#include<iostream>
#include<cstdio>
#include<cstring>
//#include<bits/stdc++.h>
using namespace std;

inline void print(int pt) {
    printf("%d\n", pt);
}
inline void print(long long pt) {
    printf("%I64d\n", pt);
}
inline void print(double pt) {
    printf("%f\n", pt);
}
inline void print(char pt[]) {
    printf("%s\n", pt);
}
inline void print(char pt) {
    printf("%c\n", pt);
}

inline void scan(int &pt) {
    scanf("%d", &pt);
}
inline void scan(long long &pt) {
    scanf("%I64d", &pt);
}
inline void scan(double &pt) {
    scanf("%lf", &pt);
}
inline void scan(char pt[]) {
    scanf("%s", pt);
}

struct pii {
    int a;
    int b;
    friend int operator<(pii a, pii b) {
        if (a.a != b.a)
            return a.a > b.a;
        return a.b < b.b;
    }
};

struct piii {
    int quest;
    int time;
    int index;

    friend int operator<(piii a, piii b) {
        if (a.quest != b.quest)
            return a.quest > b.quest;
        return a.time < b.time;
    }
};

class str {
public:
    char strr[30];
    str() {
        memset(strr, 0, sizeof(strr));
    }
    friend int operator<(str a, str b) {
        return strcmp(a.strr, b.strr) < 0;
    }
    friend int operator==(str a, str b) {
        int lena = sizeof(a.strr) / sizeof(char);
        for (int i = 0; i < lena; i++) {
            if (a.strr[i] != b.strr[i])
                return 0;
        }
        return 1;
    }
};

int bits[50];
void getbits() {
    for (int i = 0; i < 50; i++) {
        bits[i] = 1 << i;
    }
}

int n, m, k, d;
int tmp;
int x, y;
int s, t;

int main() {
    scan(t);
    while(t--){
        scan(n);
        int maxa = 0;
        while(n--){
            scan(tmp);
            maxa = max(maxa,tmp);
        }
        print(maxa);
    }

    return 0;
}