#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
const ll dim = 2*(1e6)+7;
//const ll mod = 1e9 + 7;
const ll inf = 1e17 + 77;
#define endl "\n"
#define fi first
#define pb push_back
#define se second
#define vll vector<ll>
ll n, m, k;
vll a[dim];
ll pr[dim];
ll sf[dim];
ll sz[dim];
int main() {
ll u, w,q,sm, v, y;
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >>sm>> n;
vector<pll> subs;
for(int i=1; i<=n; i++){
cin>>m;
a[i].resize(m+5);
for(int j=0; j<=m+5; j++){
sf[j]=0;
pr[j]=0;
}
ll l, r;
for(int j=1; j<=m; j++){
cin>>u;
a[i][j]=u;
pr[j]=pr[j-1]+a[i][j];
}
for(int j=m; j>=1; j--){
sf[j]=sf[j+1]+a[i][j];
}
for(int j=1; j<=m; j++){
l=pr[j];
r=sm-sf[j]+1;
if(l>=r)subs.pb({r, l});
}
}
ll ans=0;
sort(subs.begin(), subs.end());
ll end=0;
for(auto el:subs){
//cout<<el.fi<<" "<<el.se<<endl;
if(el.se<=end)continue;
ll st=max(el.fi, end+1);
if(st>el.se)continue;
ans+=(el.se-st+1);
end=el.se;
}
cout<<ans<<endl;
return 0;
}
