#include<bits/stdc++.h>
using namespace std;
int n, m, a, b;
int main()
{
	cin>>n>>m>>a>>b;
	if(a%m==1&&b%m==0)
	{
		cout<<1<<endl;
	}
	if(a%m==1&&b%m!=0)
	{
		cout<<2<<endl;
	}
	if(a%m!=1&&b%m==0)
	{
		cout<<2<<endl;
	}
	if(a%m!=1&&b%m!=0)
	{
		cout<<3<<endl;
	}	
	return 0;
}