#include<bits/stdc++.h>
using namespace std;
long long ma[30][30],f[30][30];
int x,y,n,m;
int main(){
	cin>>n>>m>>x>>y;
	//将马会攻击到的位置初始化
	ma[x][y] = 1;
	if(x-2>=0&&y+1>=0) ma[x-2][y+1] = 1;
	if(x-1>=0&&y+2>=0) ma[x-1][y+2] = 1;
	if(x+1>=0&&y+2>=0) ma[x+1][y+2] = 1;
	if(x+2>=0&&y+1>=0) ma[x+2][y+1] = 1;
	if(x-2>=0&&y-1>=0) ma[x-2][y-1] = 1;
	if(x-1>=0&&y-2>=0) ma[x-1][y-2] = 1;
	if(x+1>=0&&y-2>=0) ma[x+1][y-2] = 1;
	if(x+2>=0&&y-1>=0) ma[x+2][y-1] = 1;
	f[0][0] = 0;
	for(int i=0;i<=n;i++){
		for(int j=0;j<=m;j++){
			if(i==0&&j==0) continue;
			if(ma[i][j]==1) continue;
			else if(i==0||j==0) f[i][j] = 1;
			else f[i][j] = f[i-1][j]+f[i][j-1];
		}
	}
	cout<<f[n][m];
	return 0;
}

感觉自己写的代码没有什么问题，但就是过不了