#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define MAXN (1000005)
bool cmp(pair<ll,pair<ll,ll> > a,pair<ll,pair<ll,ll> > b){
if(a.second.first == b.second.first){ //same row
return a.second.second < b.second.second;
}else{
return a.first < b.first;
}
}
int main() {
ios_base::sync_with_stdio(false);cin.tie(0);
ll L,R;
cin>>L>>R;
vector<ll> rows[R];
ll maxlevel = 0;
ll maximum = 0;
ll prefix[R];
ll suffix[R];
memset(prefix,0,sizeof(prefix));
memset(suffix,0,sizeof(suffix));
for(ll i = 0;i < R;i++){
ll X;
cin>>X;
maxlevel = max(maxlevel,X);
ll cur = 0;
for(ll j = 0;j < X;j++){
ll a;
cin>>a;
cur += a;
rows[i].push_back(a);
}
suffix[i] = L - cur;
maximum = max(maximum,cur);
}
vector<pair<ll,pair<ll,ll> > > level; //level is the vertical thing, row is index
for(ll i = 0;i < R;i++){
ll total = 0;
for(ll j = 0;j < rows[i].size();j++){
total += rows[i][j];
level.push_back(make_pair(total,make_pair(i,j)));
}
}
sort(level.begin(),level.end(),cmp);
priority_queue<pair<ll,ll>,vector<pair<ll,ll> >,greater<pair<ll,ll> > > pq;
for(ll i = 0;i < R;i++){
pq.push(make_pair(suffix[i],i));
}
ll sum = L;
ll l = 0;
ll r = L - maximum;
ll prevr = 0;
sum -= r - prevr;
prevr = L - maximum;
for(ll i = 0;i < level.size();i++){
prefix[level[i].second.first] += rows[level[i].second.first][level[i].second.second];
l = max(l,prefix[level[i].second.first]);
prevr = max(prevr,l);
suffix[level[i].second.first] += rows[level[i].second.first][level[i].second.second];
while(pq.size() != 0 && pq.top().first != suffix[pq.top().second]){
ll a = suffix[pq.top().second];
ll b = pq.top().second;
pq.pop();
pq.push(make_pair(a,b));
}
r = pq.top().first;
sum -= max(0ll,r - prevr);
prevr = max(prevr,r);
}
cout<<sum<<'\n';
}
