#include <iostream>
#include<unordered_map>
#include <iomanip>
//#include <cstdio>
#include<vector>
#include <cmath>
#define ll long long
using namespace std;

int n,k,l,x;

vector<int> samp[1001000];
bool taken[1001000];
bool ok;
int cnt[1001000];
int missing;
int i;
int zac;
int kon;

//vector<int> last;

int main()
{
    ios::sync_with_stdio(false);
    //cout << setprecision(10);
    while(cin>>n>>k)
    {
        bool epicfail=false;
        missing=k;
        int ma=999999999;
        int cur=0;
        for(i=0; i<k+1; i++) {taken[i]=false; cnt[i]=0; samp[i].clear();}
        for(i=0; i<n; i++)
        {
            cin>>l;
            for(int j=0; j<l; j++) {
               cin>>x;
               if(!taken[x]) taken[x]=true;;
               samp[i].push_back(x);
               }
        }
        for(i=1; i<k+1; i++) {if(taken[i]==false) {cout<<-1<<endl; epicfail=true; break;}}
        if(epicfail) continue;

        zac=0;
        kon=0;
        while(missing)
        {
           for(auto it= samp[kon].begin(); it!=samp[kon].end(); ++it)
            {
                cnt[*it]++;cur++;
                if(cnt[*it]==1) missing--;
            }
            kon++;
            if(kon==n) kon=0;
        }
        ok=true;
            while(zac<n)
            {
                if(ok)
                {
                    ma=min(ma,cur);
                    for(auto it= samp[zac].begin(); it!=samp[zac].end(); ++it)
                        {
                        cnt[*it]--;cur--;
                        if(cnt[*it]==0) {ok=false; missing++;}

                        }
                    zac++;
                }

                else
                {
                    for(auto it= samp[kon].begin(); it!=samp[kon].end(); ++it)
                    {
                        cnt[*it]++;cur++;
                        if(cnt[*it]==1) missing--;
                    }
                    if(missing==0) ok=true;
                    kon++;
                    if(kon==n) kon=0;
                }



            }
            cout<<ma<<endl;
    }




    return 0;
}