```cpp
#include<bits/stdc++.h>
using namespace std;
int n,m,x,y;
int a[24][24];
long long f[24][24];
int main(){
cin>>n>>m>>x>>y;
f[2][0]=1;f[0][2]=1;
a[x+1][y+1]=1;
a[x+2][y+3]=a[x+3][y+2]=a[x+2][y-1]=a[x+3][y]=a[x][y+3]=a[x][y-1]=a[x-1][y+2]=a[x-1][y]=1;
for(int i=1;i<=n+1;i++){
for(int j=1;j<=m+1;j++){
if(!a[i][j]){
f[i][j]=f[i-1][j]+f[i][j-1];
}
}
}
cout<<f[n+1][m+1];
return 0;
}
```
by w20230071_QwQ @ 2023-06-23 17:01:26