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

namespace MyNamespace {
typedef long long ll;

inline namespace MyIO {
	inline ll rd() {
		char ch = getchar();
		ll s = 0, w = 1;
		while (!isdigit(ch)) {
			if (ch == '-') w = -1;
			ch = getchar();
		}
		while (isdigit(ch)) {
			s = (s << 3) + (s << 1) + (ch ^ 48);
			ch = getchar();
		}
		return (s * w);
	}
	template<typename T>
	inline void wr(T x) {
		if (x < 0) x = -x, putchar('-');
		if (x > 9) wr(x / 10);
		putchar(x % 10 + 48);
	}
	inline void wrsp() {
		// pass
	}
	template<typename T, typename... Args>
	inline void wrsp(T x, Args... args) {
		wr(x), putchar(' '), wrsp(args...);
	}
	inline void wrln() {
		putchar('\n');
	}
	template<typename T>
	inline void wrln(T x) {
		wr(x), putchar('\n');
	}
	template<typename T, typename... Args>
	inline void wrln(T x, Args... args) {
		wr(x), putchar(' '), wrln(args...);
	}
} // namespace MyIO

inline namespace Base {
	#define bug(x) << #x << '=' << (x) << ' '
	#define siz(A) ll((A).size())

	template<typename T>
	constexpr inline T& Max(T &x, const T &y) {
		return x = max(x, y);
	}
	template<typename T>
	constexpr inline T& Min(T &x, const T &y) {
		return x = min(x, y);
	}
} // namespace Base

constexpr int fn = 1e5;
constexpr int N = fn + 10;

int n, b[N];
template<typename T, T ini>
struct TwoMaximum {
	T fi, se;
	TwoMaximum() : fi(ini), se(ini) {}
	inline void ins(const T &k) {
		if (k >= fi) se = fi, fi = k;
		else if (k >= se) se = fi;
	}
};
int solve_tc() {
	n = rd();
	fill(b, b + n + 1, 0);
	for (int i = 1; i <= n; ++i) ++b[rd()];

	TwoMaximum<int, 0> z;
	for (int i = 1; i <= n; ++i) z.ins(b[i]);

	int ans = z.fi | z.se;
	if (z.fi & z.se) ans |= (1 << __lg(z.fi & z.se)) - 1;
	return ans;
}
void NamespaceMain() {
	int T = rd();
	while (T--) wrln(solve_tc());
}
}
int main() {
	MyNamespace::NamespaceMain();
	return 0;
}