#include <iostream>
#include <fstream>

using namespace std;

const char iname[] = "fabrica.in";
const char oname[] = "fabrica.out";
const int  nmax    = 100005;

ifstream fin(iname);
ofstream fout(oname);

int n, nra, nrb, i;
int umplere[nmax], sigilare[nmax];

int main()
{
	fin >> n >> nra >> nrb;
	for(i = 1; i <= nra; i++)
		fin >> umplere[i];
	for(i = 1; i <= nrb; i ++)
		fin >> sigilare[i];
	if(n % nra == 1)
		fout << n / nra + 1;
	else
		fout << n / nra;
	return 0;
}