#!/usr/bin/env python3
# -*- coding: utf-8-auto -*-
H, W = map(int, input().split())
A, B = map(int, input().split())
R1, C1, R2, C2 = map(int, input().split())
P, Q = map(int, input().split())

min_length = 9999999999999999999
cross_position = None
for r in range(R1, R2+1):
    for c in range(C1, C2+1):
        if min_length > abs(A-r) + abs(B-c) + abs(P-r) + abs(Q-c):
            min_length = abs(A-r) + abs(B-c) + abs(P-r) + abs(Q-c)
            cross_position = (r, c)

print(min_length + abs(P-A) + abs(Q-B))