BOJ 7575

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define MAXN 100
#define MAXM 1001

vector<int> arr[MAXN];
int pi[MAXM][MAXM];
int N,K;
int min_len = 1000;
void getpi(int start){
    int j = start;
    for (int i = start+1; i <= start+K; i++){
        while (j>start && arr[0][i] != arr[0][j]) j = pi[start][j-1];
        if (arr[0][i] == arr[0][j]){
            pi[start][i] = ++j;
        }
    }

}
bool kmp(int start){
    int cnt = 0;
    for (int k = 1 ; k< N; k++){
        bool flag = false;
        for (int kk = 0 ; kk<2&&!flag; kk++){
            int j = start;
            if(kk) reverse(arr[k].begin(),arr[k].end());
            for (int i = 0; i < arr[k].size();i++){
                while (j>start && arr[k][i]!=arr[0][j]) j =pi[start][j-1];
                if (arr[k][i] == arr[0][j]){
                    if (j == start+ K-1){
                        cnt++;
                        flag = true;
                        break;
                    }
                    else j++;
                }
            }
            if(kk) reverse(arr[k].begin(),arr[k].end());
        }
    }
    return cnt==N-1;
}
bool is_possible(){
    // 바이러스 코드가 k개인 경우 모두 조사
    for (int i= 0; i <=arr[0].size()-K; i++){
        getpi(i);
        if (kmp(i)) return true;
    }
    return false;
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> N >> K;
    for (int i = 0 ;i < N; i++){
        int m;
        cin >> m;
        min_len = min(min_len,m);
        arr[i] = vector<int>(m,0);
        for (int j = 0;j<m; j++){
            cin >> arr[i][j];
        }
    }
    bool ans = is_possible();
    if (ans) cout <<"YES\n";
    else cout <<"NO\n";
    return 0;
}