#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
typedef pair<int,P> P1;
typedef pair<P,P> P2;
#define pb push_back
#define mp make_pair
#define eps 1e-7
#define INF 1000000000
#define mod 1000000007
#define fi first
#define sc second
#define rep(i,x) for(int i=0;i<x;i++)
#define repn(i,x) for(int i=1;i<=x;i++)
#define SORT(x) sort(x.begin(),x.end())
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())
#define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin())
#define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin())
int AL[7000005],BL[7000005],CL[7000005];
int AR[7000005],BR[7000005],CR[7000005];
int n,m,x[500005],d[500005];
int mn=INF,mx=-INF;
int mn2=INF,mx2=-INF;
int main(){
	rep(i,7000005){
		AR[i]=BR[i]=CR[i]=INF;
	}
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++){
		scanf("%d%d",&x[i],&d[i]);
		mn=min(mn,x[i]);
		mx=max(mx,x[i]);
		int MN=INF,MX=-INF;
		for(int j=0;j<d[i];j++){
			int a; scanf("%d",&a);
			MN=min(MN,a);
			MX=max(MX,a);
		}
		//if(MN==MX&&MN==x[i]) assert(0);
		if(MN>=x[i]);
		else if(MX<=x[i]){
			AL[MN] = max(AL[MN],x[i]);
		}
		else{
			CL[MN] = max(CL[MN],x[i]);
		}
		if(MX>x[i]){
		    mn2 = min(mn2,x[i]);
		}
		if(MX<=x[i]);
		else if(MN>=x[i]){
			AR[MX] = min(AR[MX],x[i]);
		}
		else{
			CR[MX] = min(CR[MX],x[i]);
		}
		if(MN<x[i]){
		    mx2 = max(mx2,x[i]);
		}
		mn=min(mn,MN);
		mx=max(mx,MX);
	}
	int R = 0,ans = min(mx-mn+max(0,mx-mn2),mx-mn+max(0,mx2-mn));
	for(int i=mn;i<=mx;i++){
		if(i!=mn)ans = min(ans,mx-mn+mx-i+R);
		R = max(R,max(AL[i],CL[i]));
	}
	R = mx;
	for(int i=mx;i>=mn;i--){
		if(i!=mx)ans = min(ans,i-mn+mx-mn+mx-R);
		R = min(R,min(AR[i],CR[i]));
	}
	cout<<ans<<endl;
}