//#include <bits/stdc++.h> C++11
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>
#include <stdio.h>
#include <time.h>
#include <iomanip>
#include <stdlib.h>
#include <list>
#include <stack>
#include <queue>
#include <climits>
#include <map>
#include <set>
#include <sstream>
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef vector<int> vi;
#define PB push_back
#define MP make_pair
int HashFunction(int k){
return (k*167-1)*131-k*3;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int L, R, X, temp;
cin >> L >> R;
vi append;
vector<vi> wall;
int flag, maxx;
flag = 1;
maxx = 0;
for (int i = 0; i < R; i++)
{
cin >> X;
if (X > 1)
{
flag = 0;
}
cin >> temp;
maxx = max(maxx, temp);
append.PB(temp);
for (int j = 1; j < X; j++)
{
cin >> temp;
maxx = max(maxx, temp);
append.PB(temp+append[j-1]);
}
wall.PB(append);
append.clear();
}
if (flag == 1)
{
cout << max(2 * maxx - L, 0) << "\n";
}
if (flag == 0)
{
vi blocked(L,0);
int space;
int count=0;
for (int i = 0; i < R; i++)
{
for(int j=0;j<int(wall[i].size());j++){
if(j==0){
space=L-(wall[i][int(wall[i].size())-1]-wall[i][j]);
//cout<<"space (for wall "<<j<<" in line "<<i<<") = "<<space<<"\n";
for(int k=space-wall[i][j];k<wall[i][j];k++){
if(blocked[k]==0){
blocked[k]=1;
count++;
}
}
}
else{
space=L-(wall[i][int(wall[i].size())-1]-wall[i][j])-wall[i][j-1];
//cout<<"space (for wall "<<j<<" in line "<<i<<") = "<<space<<"\n";
for(int k=wall[i][j-1]+space-(wall[i][j]-wall[i][j-1]);k<wall[i][j];k++){
if(blocked[k]==0){
blocked[k]=1;
count++;
}
}
}
}
}
cout << count << "\n";
}
}
