#include <bits/stdc++.h>
using namespace std;
int te() {
	// read input
	int n;
	scanf("%d", &n);
	vector<int> a(n);
	for(int i = 0; i < n; ++i)
		scanf("%d", &a[i]);
	// sort
	sort(a.begin(), a.end());
	// check if some two numbers are equal
	for(int i = 0; i < (int) a.size() - 1; ++i)
		if(a[i] == a[i+1])
			return a[i];
	// check if the first (smallest) numbers are consecutive
	// if not then the smallest number should be removed
	if(a[0] + 1 != a[1]) return a[0];
	return a.back(); // otherwise the biggest number
}
	
int main() {
	int T;
	scanf("%d", &T);
	while(T--) printf("%d\n", te());
}