LCS

#include <bits/stdc++.h>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int T;
    cin >> T;
    while(T--) {
        int N, M;
        cin >> N >> M;
        string s, t;
        cin >> s >> t;
        vector < vector < int > > dp(N + 1, vector < int >(M + 1));
        for(int i = 1; i <= N; ++i)
            for(int j = 1; j <= M; ++j) {
                if(s[i - 1] == t[j - 1])
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                else
                    dp[i][j] = max(dp[i][j], max(dp[i - 1][j], dp[i][j - 1]));
            }
        cout << dp[N][M] << '\n';
    }
}