#include <bits/stdc++.h>

typedef long long ll;
typedef long double ld;

using namespace std;

#define rep(i, a, n) for (int i = (a); i < (n); i++)
#define per(i, a, n) for (int i = (n) - 1; i >= (a); i--)
const int INF = 1000000000;

int main(void) {
	ios::sync_with_stdio(false);
	int n, k;
	while(cin>>n>>k) {
        vector<vector<int>> a(n*2);
        rep(i,0,n) {
            int m;
            cin >> m;
            rep(j,0,m) {
                int x;
                cin >> x;
                a[i].push_back(x-1);
            }
        }
        rep(i,0,n) {
            a[i+n] = a[i];
        }
        vector<int> cur(k,0);

        int to = 0;
        int tot = 0;
        int missing = k;
        int res = INF;
        rep(fr,0,n*2) {
            while(missing > 0 && to < n*2) {
                for(auto &x : a[to]) {
                    if(cur[x] == 0) missing--;
                    cur[x]++;
                }
                tot+=a[to].size();
                to++;
            }
            if (missing == 0) {
                res = min(res, tot);
            }

            for (auto &x : a[fr]) {
                cur[x]--;
                if(cur[x] == 0) missing++;
            }
            tot -= a[fr].size();
        }
        if (res == INF) {
            cout << -1 << endl;
        } else
            cout << res << endl;
	}

	return 0;
}