#include <string>
#include <vector>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<stack>
#include<queue>
#include<cmath>
#include<algorithm>
#include<functional>
#include<list>
#include<deque>
#include<bitset>
#include<set>
#include<map>
#include<unordered_map>
#include<cstring>
#include<sstream>
#include<complex>
#include<iomanip>
#include<numeric>
#define X first
#define Y second
#define pb push_back
#define rep(X,Y) for (int (X) = 0;(X) < (Y);++(X))
#define rrep(X,Y) for (int (X) = (Y-1);(X) >=0;--(X))
#define repe(X,Y) for ((X) = 0;(X) < (Y);++(X))
#define peat(X,Y) for (;(X) < (Y);++(X))
#define all(X) (X).begin(),(X).end()
#define rall(X) (X).rbegin(),(X).rend()

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
template<class T> using vv=vector<vector<T>>;
template<class T> ostream& operator<<(ostream &os, const vector<T> &t) {
os<<"{"; rep(i,t.size()) {os<<t[i]<<",";} os<<"}"<<endl; return os;}
template<class S, class T> ostream& operator<<(ostream &os, const pair<S,T> &t) { return os<<"("<<t.first<<","<<t.second<<")";}

int main(){
  ios_base::sync_with_stdio(false);
  cout<<fixed<<setprecision(0);
  int i,j,k;
  int n,a,c;
  cin>>n>>a;
  vector<int> b(a);
  rep(i,a)
    cin>>b[i];
  cin>>c;
  vector<int> d(c);
  rep(i,c)
    cin>>d[i];
  sort(all(d));
  vector<int> v(n);
  rep(i,n)
    v[i]=d[i%c];
  multiset<int> s;
  int re=0;
  rep(i,n){//cout<<i<<endl;
    if(i%a==0)
      s=multiset<int>(all(b));
    //cout<<"{";for(int tmp:s)cout<<tmp<<" ";cout<<endl;
    auto it=s.upper_bound(v[i]);
    if(it!=s.end()){
      ++re;
      s.erase(it);
    }else{
      s.erase(s.begin());
    }
    //cout<<"{";for(int tmp:s)cout<<tmp<<" ";cout<<"}"<<endl;
  }
  cout<<re<<endl;
  return 0;
}