#include<stdio.h>
int abs(int n)
{
	if (n < 0)
		return -n;
	else
		return n;
}
int main()
{
	int h, w;
	scanf("%d %d", &h, &w);
	int a, b;
	scanf("%d %d", &a, &b);
	int r1, c1, r2, c2;
	scanf("%d %d %d %d", &r1, &c1, &r2, &c2);
	int p, q;
	scanf("%d %d", &p, &q);
	int ans = 1e9;
	int i, j;
	int v;
	for (i = r1; i <= r2; i++)
	{
		for (j = c1; j <= c2; j++)
		{
			v = abs(a - i) + abs(b - j);
			v += abs(p - i) + abs(q - j);
			v += abs(a - p) + abs(b - q);
			if (ans > v)
				ans = v;
		}
	}
	printf("%d\n", ans);
	return 0;
}