#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
const ll mod=1e9+7;
const ll maxn=5e5+5;
const ll INF=1e18;
#define ok ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define fi first
#define se second
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define endl '\n'
int l, r, x, u, sum[maxn], ls, st, cnt;
vi row[maxn];
map<int, int> mp, ans;
int main() {
ok
cin >> l >> r;
for(int i=1; i<=r; i++) {
cin >> x;
for(int j=0; j<x; j++) {
cin >> u;
row[i].pb(u);
sum[i]+=u;
}
}
for(int i=1; i<=r; i++) {
mp[l-sum[i]+1]++;
mp[l+1]--;
int lf=0, rg=l-sum[i]+1;
x=row[i].size();
for(int j=0; j<x-1; j++) {
lf+=row[i][j];
rg+=row[i][j];
mp[1]++;
mp[lf+1]--;
mp[rg]++;
mp[l+1]--;
}
mp[1]++;
mp[sum[i]+1]--;
ls=0; st=0;
for(auto it : mp) {
it.se+=ls;
ls=it.se;
if(it.se==x+1 && !st) {
st=it.fi;
} else if(it.se!=x+1 && st) {
ans[st]++;
ans[it.fi]--;
st=0;
}
}
mp.clear();
}
ls=0; st=0;
for(auto it : ans) {
it.se+=ls;
ls=it.se;
if(it.se>0 && !st) {
st=it.fi;
} else if(it.se<=0 && st) {
cnt+=it.fi-st;
st=0;
}
}
cout << cnt;
}
