#include<bits/stdc++.h>
using namespace std;
#define int long long
#define in pair<int, int>
#define f first
#define s second
#define pb push_back
#define pob pop_back
#define INF (int)1e17
#define MX (int)3e5+5
#define LMX (int)2e6+69
#define fast() ios_base::sync_with_stdio(false); cin.tie(NULL)
int ok(int a, int b, int c)
{
//in [a, b] with <= c
if(c < a)
return 0;
return min(b, c)-a+1;
}
struct seg_tree
{
vector<int> tree;
void init(int n)
{
tree.assign(4*n+69, 0);
return;
}
void upd(int val, int pos, int id, int l, int r)
{
if(l == r)
{
tree[id] = val;
return;
}
int m = (l+r)/2;
if(pos <= m)
upd(val, pos, 2*id, l, m);
else
upd(val, pos, 2*id+1, m+1, r);
tree[id] = min(tree[2*id], tree[2*id+1]);
return;
}
int rep()
{
return tree[1];
}
};
signed main()
{
fast();
seg_tree work;
int L, n;
cin >> L >> n;
work.init(n);
vector<in> p;
vector<int> v;
vector<int> a(n+1);
for(int i = 1; i <= n; i++)
{
int c;
cin >> c;
v.resize(c+1);
v[0] = 0;
for(int j = 1; j <= c; j++)
{
cin >> v[j];
v[j]+=v[j-1];
p.pb({v[j], i});
}
a[i] = L-v[c];
}
int ans = 0;
for(int i = 1; i <= n; i++)
work.upd(a[i], i, 1, 1, n);
sort(p.begin(), p.end());
p.pb({L, 1});
vector<int> upd;
int prev = 0;
for(auto [pr, W]: p)
{
if(pr > prev)
ans+=ok(prev+1, pr, work.rep());
prev = pr;
work.upd(pr+a[W], W, 1, 1, n);
}
ans = L-ans;
cout << ans << "\n";
return 0;
}
