#include<bits/stdc++.h>
using namespace std;
#define int long long
int t, n1, m1;
string s11, s22;
inline int read() {
	int x = 0, f = 1;
	char ch = getchar();
	while (ch < '0' || ch > '9') {
		if (ch == '-')
			f = -1;
		ch = getchar();
	}
	while (ch >= '0' && ch <= '9') {
		x = (x << 3) + (x << 1) + (ch ^ 48);
		ch = getchar();
	}
	return x * f;
}
inline void write(int x) {
	if (x < 0) {
		putchar('-');
		x = -x;
	}
	if (x > 9)
		write(x / 10);
	putchar(x % 10 + '0');
}
bool judge(string s1, string s2, int n, int m) {
	int i = 0, j = 0, ans = 0;
	bool f = 0;
	while (j < m) {
		if (i >= n) {
			cout << i << " " << j << "\n";
			int l = m - j;
			int p = i - l;
			//u和p
			int u = j;
			//cout << u << " " << p << "\n";
			bool flag = 1;
			for (int o = 0; o < l; o++) {
				if (s1[p + o] != s2[u + o]) {
					flag = 0;
					break;
				}
			}
			if (flag) return true;
			else return false;
		} else {
			if (s1[i] == s2[j]) {
				if (f) {
					ans++;
					f = 0;
				}
				i++;
				j++;
			} else {
				j++;
				f = 1;
			}
		}
	}
	if (ans >= 2) return false;
	else return true;
}
signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	cin >> t;
	while (t--) {
		cin >> n1 >> m1;
		cin >> s11 >> s22;
		if (n1 == m1) {
			if (s11 == s22) cout << "Yes\n";
			else cout << "No\n";
			continue;
		} else {
			if (judge(s11, s22, n1, m1)) cout << "Yes\n";
			else cout << "No\n";
		}
	}
	return 0;
}