#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; }