#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
#define ll long long
#define ld long double
#define inf (ll)(2*1e18)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define pb push_back
#define endl "\n"
using namespace std;
void solve(){
ll n, q, i, j, k, l, r, x, y, cnt=0;
cin>>n>>q;
vector<ll> ansl;
vector<ll> ansr;
for(i=0;i<q;++i){
cin>>k;
vector<ll> b(k);
vector<ll> c(k);
vector<ll> d(k);
for(j=0;j<k;++j){
cin>>b[j];
}
for(j=1;j<k;++j){
c[j] = c[j-1] + b[j-1];
}
for(j=k-2;j>=0;--j){
d[j] = d[j+1] + b[j+1];
}
for(j=0;j<k;++j){
x = n - c[j] - d[j];
y = x - b[j];
if(y < b[j]){
ansl.pb(y + c[j]);
ansr.pb(b[j] + c[j]);
}
}
}
sort(ansl);
sort(ansr);
if(ansr.size() >= 1) cnt += ansr[0] - ansl[0];
for(i=1;i<ansr.size();++i){
cnt += min(ansr[i] - ansr[i-1], ansr[i] - ansl[i]);
}
cout<<cnt<<endl;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
srand(time(nullptr));
ll t=1;
// cin>>t;
for(;t>0;--t){
solve();
}
return 0;
}
