#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define int long long
#define pii pair<int, int>
#define ff first
#define ss second
#define entire(x) (x).begin(), (x).end()
int32_t main(){
ios::sync_with_stdio(false); cin.tie(nullptr);
int m, n; cin >> m >> n; // m = row size
vector<vector<int>> row(n);
for (int i = 0; i < n; i++){
int x; cin >> x;
for (int j = 0, w; j < x; j++) cin >> w, row[i].push_back(w);
}
// only the regions with interval depth n will survive
// start === {coord, 1}, end === {coord, -1} // [start, end)
vector<pii> safe;
auto solve = [&](vector<int> a){
int nr = (int) a.size();
int bef = 0, aft = accumulate(entire(a), 0ll);
safe.push_back(pii{0, 1}); safe.push_back(pii{m - aft, -1});
int pos = m - aft;
for (int i = 0; i < nr; i++){
bef += a[i]; aft -= a[i];
pos = max(pos, bef);
safe.push_back(pii{pos, 1});
pos = m - aft;
safe.push_back(pii{pos, -1});
}
};
for (auto a : row) solve(a);
sort(entire(safe));
int depth = 0, last = 0, ans = 0;
for (auto [pos, type] : safe){
if (type == 1) { depth++, last = pos; continue; }
if (type == -1) {
if (depth == n) ans += pos - last;
last = pos; depth--;
}
}
cout << m - ans << endl;
return 0;
}
