60TLE分求助！！！

#include<bits/stdc++.h>
using namespace std;
int fx, fy, p = 0, sx, sy;
bool vist[40][40];
int ax[10] = {-2, -1, 1, 2, 2, 1, -1, -2};
int ay[10] = {1, 2, 2, 1, -1, -2, -2, -1};
int cx[4] = {1, 0};
int cy[4] = {0, 1}; 
void mg(int nx, int ny){
	int i;
	if(nx == sx && ny == sy){
		p++;
		return;	
	}
	for(i = 0;i < 2; ++i){
		int kx, ky;
		kx = nx + cx[i];
		ky = ny + cy[i];
		if(vist[kx][ky] == 1)continue;
		if(kx < 0 || kx > sx || ky < 0 || ky > sy)continue;
		vist[kx][ky] = 1;
		mg(kx, ky);
		vist[kx][ky] = 0;
	}
	
}
int main(){
	cin >> sx >> sy >> fx >> fy;
	vist[fx][fy] = 1;
	int tx, ty;
	for (int j = 0; j < 8; ++j){
		tx = fx + ax[j];
		ty = fy + ay[j];
		if(tx <= 0 || tx > sx || ty <= 0 || ty > sy)continue;
		vist[tx][ty] = 1;
	}
	mg(0, 0);
	cout << p;
return 0;
}