#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;
a[i].push_back(u);
}
}
ll count = 0;
for (int i = 0; i < l; i++) {
ll countif = 0;
for (int row = 0; row < r; row++) {
ll cur = 0;
ll curback = 0;
ll right = 0;
for (int j = 0; j < a[row].size(); j++) {
if (right == 1) {
curback += a[row][j];
} else if (right == 0 and cur + a[row][j] < i) {
cur += a[row][j];
} else {
right = 1;
curback += a[row][j];
}
}
if (!(cur < i and curback < l - i - 1)) {
countif++;
}
}
if (countif != r) {
count++;
}
}
cout << count << "\n";
}
