#include <bits/stdc++.h>
using namespace std;
#define loop(i,n) for (ll i = 0; i < n; i++)
#define ll long long
#define INF 1e9+5
#define MAXN 300007
#define pb push_back
#define mp make_pair
typedef pair<ll,ll> pii;
int main(){
ll l,r,i,j,k,x,maxi=0;
cin>>l>>r;
vector<vector<ll>>row(r);
vector<vector<ll>>dp(r);
for(i=0;i<r;i++){
cin>>x;
maxi=max(maxi,x);
dp[i].pb(0);
for(j=1;j<=x;j++){
cin>>k;
row[i].pb(k);
dp[i].pb(dp[i][j-1]+k);
}
}
if(maxi==1){//só há um por linha
ll savedL=INF, savedR=-1;
for(i=0;i<r;i++){
k=row[i][0];
savedR = max(savedR , k);
savedL = min(savedL, l-k-1);
}
k = savedL+1;
savedR=max(savedR,savedL+1);
k+=(l-savedR);
printf("%lld\n",l-k);
}else{
ll left, right,m,cur=0;
vector<pii>overall;
for(i=0;i<r;i++){
m=dp[i][dp[i].size()-1];
vector<pii>intervals;
if(m==l){
cout<<l<<'\n';
return 0;
}
for(j=0;j<(ll)dp[i].size();j++){
left=dp[i][j]+1;
right=l-(m-left)-1;
if(left>right)continue;
intervals.pb({ left,1 });
intervals.pb({ right+1,-1 });//a partir de right, não está safe
}
sort(intervals.begin(),intervals.end());
for(j=0;j<(ll)intervals.size();j++){
cur+=intervals[j].second;
while(j+1<(ll)intervals.size() && intervals[j+1].first==intervals[j].first){
j++;
cur+=intervals[j].second;
}
if(cur==0){
//a partir desta posição, os lasers foram apanhados em todas as configurações
if(j==(ll)intervals.size()-1){
overall.pb({ intervals[j].first, 1 });
overall.pb({ l+1, -1 });
}else{
overall.pb({ intervals[j].first, 1 });
overall.pb({ intervals[j+1].first, -1 });
}
}
}
}
sort(overall.begin(),overall.end());
/*
for(j=0;j<(ll)overall.size();j++){
cout<<overall[j].first<<" "<<overall[j].second<<" ";}
cout<<endl;*/
cur=0; ll ans=0;
for(i=0;i<(ll)overall.size();i++){
if(overall[i].first==l+1)break;
cur+=overall[i].second;
while(i<(ll)overall.size()-1 && overall[i+1].first==overall[i].first){
i++;
cur+=overall[i].second;
}
if(cur>0){
ans+=(overall[i+1].first-overall[i].first);
}
}
cout<<ans<<endl;
}
return 0;
}
