#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef deque<int> dqi;
typedef pair<ll, ll> pll;
#define ppf pop_front
#define pf push_front
#define pb push_back
#define fr first
#define sc second
#define all(a) a.begin(), a.end()
#define sr(a) sort(all(a))
#define sz(a) a.size()
#define rep(x, a, b) for(auto x=a;(a<b?x<b:x>b);(a<b?x++:x--))
#define mnto(x,y) x = min(x, (__typeof__(x))y)
#define mxto(x,y) x = max(x, (__typeof__(x))y)
const ll INF1 = 1e18;
const ll INF2 = 1e15;
const ll INF3 = 1e14;
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
ll l;
int r, x;
cin >> l >> r;
vector<pll> avail;
rep(i, 0, r) {
cin >> x;
vll a(x);
rep(i, 0, x) cin >> a[i];
vll ps(x+1, 0);
rep(i, 0, x) ps[i+1] = ps[i]+a[i];
ll total = ps[x];
ll d = l-total; //remaining guranteed spaces
rep(j, 0, x) {
ll leftl = ps[j]+1;
ll leftr = ps[j]+a[j];
ll rightl = leftl+d;
ll rightr = leftr+d;
ll gl = max(leftl, rightl);
ll gr = min(leftr, rightr);
if (gl <= gr) {
avail.emplace_back(gl, gr);
}
}
}
sr(avail);
vector<pll> merged;
for (auto [l, r] : avail) {
if (!sz(merged) || l > merged.back().sc+1) merged.emplace_back(l, r);
else mxto(merged.back().sc, r);
}
ll ans = 0;
for (auto [l, r] : merged) ans += r-l+1;
cout << ans;
}
