#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define f first
#define s second
#define pii pair<int, int>
#define MX(a,b) a=max(a,b)
#define MN(a,b) a=min(a,b)
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(), (x).end()
#define REP(i,n) for (int i = 0; i<n; ++i)
#define REP1(i,n) for (int i = 1; i<=n; ++i)
#define pb push_back
#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<": "<<#__VA_ARGS__<<"- ", _do(__VA_ARGS__)
template<typename T> void _do( T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do( T && x, S && ...y) {cerr<<x<<", "; _do(y...);}
#else
#define bug(...)
#define endl '\n'
#endif // BALBIT
const int maxn = 3e5+5;
signed main(){
ios::sync_with_stdio(0), cin.tie(0);
bug(1,2);
int L,n; cin>>L>>n;
vector<pii> seg;
REP(rnd,n) {
int k; cin>>k;
vector<int> a(k);
vector<int> ps(k+1);
int tot = 0;
REP(i,k) {
cin>>a[i]; tot += a[i];
ps[i+1] = ps[i] + a[i];
}
REP(i,k) {
int l = L - (tot - ps[i]) + 1, r = ps[i+1];
if (l <= r) {
seg.pb({l,1}); seg.pb({r+1, -1}); bug(l,r);
}
}
}
sort(ALL(seg));
int prv = 1;
int cnt = 0;
int re = 0;
for (pii p : seg) {
if (cnt) {
re += p.f - prv;
}
cnt += p.s;
prv = p.f;
}
cout<<re<<endl;
}
