#include <bits/stdc++.h>
#include <stdio.h>
#include <cinttypes>

using namespace std;

#define DEB(x) cout << #x << " = " << x << endl;

int main(void) {
    int n, k;

    while (scanf("%d %d", &n, &k) == 2) {
        vector<pair<int, set<int> > > samps;
        samps.reserve(n);
        for (int i = 0; i < n; i++) {
            set<int> samp;
            int samcnt;
            scanf("%d", &samcnt);
            int samx;
            for (int j = 0; j < samcnt; j++) {
                scanf("%d", &samx);
                samp.insert(samx);
            }
            samps.push_back(make_pair(samcnt, samp));
        }

        int best = -1;
        for (int i = 0; i < n; i++) {
            set<int> mame(samps[i].second.begin(), samps[i].second.end());
            int cnt = samps[i].first;
            int j = (i + 1) % n;
            while (j != i && mame.size() < k) {
                mame.insert(samps[j].second.begin(), samps[j].second.end());
                cnt += samps[j].first;
                j = (j + 1) % n;
            }

            if (i == 0 && mame.size() < k) {
                best = -1;
                break;
            }

            if (best == -1 || best > cnt) {
                best = cnt;
            }
        }
        printf("%d\n", best);
/*
        for (auto& p: samps) {
            DEB(p.first)
            cout << "brands" << endl;
            for (auto& s : p.second) {
                DEB(s)
            }
            cout << endl;
        }
        cout << "END" << endl;
*/

    }

    return 0;
}