#include <bits/stdc++.h>
#define N 1000005
#define ll long long int
#define MP make_pair
#define pb push_back
#define ppb pop_back
#define sp " "
#define endl "\n"
#define fi first
#define se second
#define ii pair<int,int>
#define lli pair<ll,ll>
#define fast cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(false)
#define fast2 freopen ("badhair.gir","r",stdin);freopen ("badhair.cik","w",stdout);
#define mod 1000000007
#define fs(x,y) for(ll i=1;i<=y;i++) cin>>x[i]
#define fo(i,x,y) for(ll i=x;i<=y;i++)
#define INF 1000000000005
#define ull unsigned long long int
using namespace std;
ll n,m,ar[N],sum,t,l,suf[N];
vector<lli> v;
int main()
{
fast;
// cout<<endl;
cin>>l>>t;
while(t--)
{
cin>>n;
ll top=0;
fs(ar,n);
int ind=1;
fo(i,1,n+1)
suf[i]=0;
for(int i=n;i>=1;i--)
suf[i]=suf[i+1]+ar[i];
fo(i,1,n)
{
ind=top;
ll x=suf[i+1];
x+=ind;
x=l-x;
x=2*ar[i]-x;
top+=ar[i];
if(x<=0)
continue;
ind++;
ll y=ar[i]-x;
// cout<<i<<sp<<ind<<sp<<x<<sp<<y<<endl;
v.pb({ind+y,ind+y+x-1});
}
}
sort(v.begin(),v.end());
ll mk=0;
for(int i=0;i<v.size();i++)
{
ll a=v[i].fi;
ll b=v[i].se;
if(b<mk)
continue;
mk=max(mk+1,a);
sum+=b-mk+1;
mk=max(mk,b);
}
cout<<sum;
}
