#include <bits/stdc++.h>
using namespace std;
int n, m, t, d[15][15], dp[15][15];

int main() {
	cin >> n >> m >> t;
	int x, y, xx, yy;
	cin >> x >> y >> xx >> yy;
	while (t--) {
		int x, y;
		cin >> x >> y;
		d[x][y] = 1;
	}
	for (int i = 1; i <= xx; i++) {
		for (int j = 1; j <= yy; j++) {
			if (d[i][j] == 0) {
				dp[i][j] = max(max(dp[i - 1][j], dp[i][j - 1]), max(dp[i + 1][j], dp[i][j + 1]));
				if (i == 1 || j == 1)
					dp[i][j] = 1;
			}
		}
	}
	cout << dp[xx][yy];

	return 0;
}