#include <bits/stdc++.h>
using namespace std;
#define int long long
#define rep(i,a,b) for(int i = a; i <= b; i++)
#define per(i,a,b) for(int i = a; i >= b; i--)
#define pii pair<int,int>
#define pb push_back
#define fi first
#define se second
const int MAXN = 5e5+10;
const int INF = 1e18+10;
int dif[1000001];
int32_t main() {
ios_base::sync_with_stdio(0); cin.tie(nullptr);
int L,m;cin >> L >> m;
vector<vector<pii>> ranges(m+1);
rep(i,1,m) {
int j, s=0;cin >> j;
vector<int> a;
while (j--) {
int x;cin >> x;
a.pb(x);
s += x;
}
int cur = 0;
for (int &x : a) {
cur += x;
if(L-s+1<=cur)ranges[i].pb({L-s+1,cur});
s-=x;
}
}
rep(i,1,m) {
for (auto &[l,r] : ranges[i]) dif[l]++, dif[r+1]--;
}
int cnt = 0, cur = 0;
rep(i,1,1000000) {
cur+=dif[i];
cnt += min(cur,1LL);
}
cout << cnt << '\n';
return 0;
}
