#include<cstdio>
#include<iostream>
using namespace std;
int a,b,m,ans=999999,e;
int main()
{
	freopen("cowroute.in","r",stdin);
	freopen("cowroute.out","w",stdout);
	cin>>a>>b>>m;
	for(int i=1;i<=m;i++)
	{
		int c,d,now;
		cin>>c>>d;
		now=0;
		for(int j=1;j<=d;j++)
		{
			cin>>e;
			if(e==a)
			{
				now=1;
				//cout<<a<<endl;
				//cout<<i<<" "<<e<<" "<<j<<endl;
				//cout<<now<<endl;
			}
			if(e==b&&now==1)
			{
				if(ans>c)
					ans=c;
			}
		}
	}
	if(ans==999999)
		printf("%d",-1);
	else
		printf("%d",ans);
	return 0;
}