https://www.luogu.com.cn/record/173726586

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ri register int
#define Lf long double
#define lf double
#define ii inline int
#define iv inline void
#define ib inline bool
#define il inline ll
#define is inline string
#define ci const int
#define vi vector<int>
#define pq priority_queue
#define di deque<int>
#define pr pair<int, int>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define inf 0x3f3f3f3f
#define infll 0x3f3f3f3f3f3f3f3f
#define mod 1000000007
#define N 1005
#define endl '\n'
#define int ll
vector<bitset<N>>m(N);
int n, M, T, a, b, sx, sy, fx, fy,ans;
iv dfs(int x, int y)
{
    if ((x == fx && y == fy)){
        ans++;return;
    }if(x>fx||y>fy||m[x][y]||x<1||y<1)return;
    m[x][y] = 1;
    dfs(x + 1, y);
    dfs(x, y + 1);
    dfs(x - 1, y);
    dfs(x, y - 1);
    m[x][y] = 0;
}
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> M >> T;
    cin >> sx >> sy >> fx >> fy;
    while (T--)
        cin >> a >> b, m[a][b] = 1;
    dfs(sx, sy);
    cout << ans;
    return 0;
}