#include <bits/stdc++.h>
#define int long long
using namespace std;
int T, n, m, a[100005], b[100005];
int main() {
//	freopen("magic.in", "r", stdin);
//	freopen("magic.out", "w", stdout);

	cin >> T;
	while(T--) {
		cin >> n >> m;
		for(int i = 1; i <= n; i++) cin >> a[i];
		for(int i = 1; i <= m; i++) cin >> b[i];
		sort(a + 1, a + n + 1);
		sort(b + 1, b + m + 1); 
		b[m + 1] = 2e9, b[0] = -2e9;
		int ans = 0;
		for(int i = 1; i <= m + 1; i++) {
			int r = lower_bound(a + 1, a + n + 1, b[i]) - a - 1;
			int l = upper_bound(a + 1, a + n + 1, b[i - 1]) - a;
			ans =max(ans, r - l + 1);
		}
		cout << max(ans, 0) << endl;
	}	
	return 0;
}