#include <bits/stdc++.h>

using namespace std;

int main()
{
	int x1 = 0;
	int x2 = 0;
	int y1 = 0;
	int y2 = 0;
	cin >> x1; cin >> y1;
	cin >> x2; cin >> y2;
	if (x1 == x2 || y1 == y2)
	{
		cout << 2;
	}
	if (abs(x1-x2) == abs(y1-y2))
	{
		cout << 1;
	}
	else cout << 0;
	return 0;
}