#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Interval = pair<ll,ll>;
vector<Interval> merge_intervals(vector<Interval> a) {
vector<Interval> res;
if (a.empty()) return res;
sort(a.begin(), a.end());
ll curL = a[0].first, curR = a[0].second;
for (size_t i = 1; i < a.size(); ++i) {
if (a[i].first <= curR + 1) {
curR = max(curR, a[i].second);
} else {
res.emplace_back(curL, curR);
curL = a[i].first;
curR = a[i].second;
}
}
res.emplace_back(curL, curR);
return res;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
ll L;
int R;
if (!(cin >> L >> R)) return 0;
vector<Interval> global_forced; // collect forced intervals from all rows
for (int row = 0; row < R; ++row) {
int X;
cin >> X;
vector<ll> W(X);
for (int i = 0; i < X; ++i) cin >> W[i];
// prefix sums P_m (P_0 = 0,...,P_X = T)
vector<ll> P(X+1, 0);
for (int i = 1; i <= X; ++i) P[i] = P[i-1] + W[i-1];
ll T = P[X];
// collect avoidable intervals [P_m+1, L - (T - P_m)]
vector<Interval> avoid;
for (int m = 0; m <= X; ++m) {
ll l = P[m] + 1;
ll r = L - (T - P[m]);
if (l <= r) {
// clamp to [1,L] although l,r already in that range logically
if (r < 1 || l > L) continue;
l = max<ll>(l, 1);
r = min<ll>(r, L);
if (l <= r) avoid.emplace_back(l, r);
}
}
// merge avoid intervals
auto avoidm = merge_intervals(avoid);
// complement in [1,L] -> forced intervals for this row
ll cur = 1;
for (auto &iv : avoidm) {
if (cur <= iv.first - 1) {
global_forced.emplace_back(cur, iv.first - 1);
}
cur = iv.second + 1;
}
if (cur <= L) global_forced.emplace_back(cur, L);
// note: if avoidm is empty, forced is [1,L] (handled by cur=1 case)
}
// merge all forced intervals across rows and sum lengths
auto merged = merge_intervals(global_forced);
ll ans = 0;
for (auto &iv : merged) {
ans += (iv.second - iv.first + 1);
}
cout << ans << '\n';
return 0;
}
