#include <bits/stdc++.h>
using ll = long long;
using namespace std;
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
ll l, r;
cin >> l >> r;
vector<vector<ll>> a(r);
for (int i = 0; i < r; i++) {
ll x;
cin >> x;
for (int j = 0; j < x; j++) {
ll u;
cin >> u;
if (j == 0)
a[i].push_back(u);
else {
a[i].push_back(u + a[i][j - 1]);
}
}
}
ll count = 0;
for (int i = 0; i < l; i++) {
ll countif = 0;
for (int row = 0; row < r; row++) {
ll left = a[row].back(), right = 0;
for (int j = 0; j < a[row].size(); j++) {
if (a[row][j] > i) {
if (j == 0) {
left = 0;
right = a[row][a[row].size() - 1];
break;
} else {
left = a[row][j - 1];
right = a[row][a[row].size() - 1] - a[row][j - 1];
break;
}
}
}
if (right <= l - i - 1) {
countif++;
}
}
if (countif != r) {
count++;
}
}
cout << count << "\n";
}
