#include <iostream>
#include <string>
using namespace std;
 
bool canTransform(string s, string t) {
    int n = s.size(), m = t.size();
    // 如果 t 本身就是 s 的子串（不需要操作的情况）
    if (s.find(t) != string::npos) {
        return true;
    }
    // 尝试所有可能的子串删除并添加到末尾的操作
    for (int l = 0; l < n; ++l) {
        for (int r = l; r < n; ++r) {
            // 构造新的字符串：s 去掉 [l, r] 子串，然后将该子串添加到末尾
            string new_s = s.substr(0, l) + s.substr(r + 1) + s.substr(l, r - l + 1);
            if (new_s == t) {
                return true;
            }
        }
    }
    return false;
}
 
int main() {
    int T;
    cin >> T;
    while (T--) {
        int n, m;
        cin >> n >> m;
        string s, t;
        cin >> s >> t;
        if (canTransform(s, t)) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }
    }
    return 0;
}

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