$RE1,4$

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,m,x,y,dp[10005][10005],a[10005][10005];
signed main()
{
    scanf("%lld%lld%lld%lld",&n,&m,&x,&y);
    a[x-2][y-1]=1;
	a[x-2][y+1]=1;
	a[x-1][y+2]=1;
	a[x-1][y-2]=1;
	a[x+1][y+2]=1;
	a[x+2][y+1]=1;
	a[x+2][y-1]=1;
	a[x+1][y-2]=1;
	a[x][y]=1;
	a[0][0]=1;
	dp[0][0]=1;
    for(int i=0;i<=n;i++)
	{
        for(int j=0;j<=m;j++)
		{
			if(a[i][j]==0)
			{
				if(j==0)dp[i][j]=dp[i-1][j];
				else if(i==0)dp[i][j]=dp[i][j-1];
				else dp[i][j]=dp[i-1][j]+dp[i][j-1];
			}
        }
    }
    printf("%lld",dp[n][m]);
    return 0;
}