#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int N,M;
vector<pair<int,int>> E[201010];
ll D[202020];

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>M;
	FOR(i,M) {
		cin>>k>>x;
		FOR(j,k) {
			cin>>y;
			E[y].push_back({i+N+1,x+y});
			E[i+N+1].push_back({y,x+y});
		}
	}
	FOR(i,202020) D[i]=1LL<<60;
	D[1]=0;
	priority_queue<pair<ll,int>> Q;
	Q.push({0,1});
	while(Q.size()) {
		ll co=-Q.top().first;
		int cur=Q.top().second;
		Q.pop();
		if(D[cur]!=co) continue;
		if(cur<=N && co%2) co++;
		
		if(cur==N) {
			cout<<co/2<<endl;
			return;
		}
		
		FORR2(e,c,E[cur]) if(D[e]>co+c) {
			D[e]=co+c;
			Q.push({-D[e],e});
		}
		
		
	}
	cout<<-1<<endl;
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}