//ZJU 1047 Image Perimeters

//2003.08.04 BY ADAI

#include <iostream>

using namespace std;

int a[22][22];

int movex[8]={-1,-1,-1,0,1,1,1,0};

int movey[8]={-1,0,1,1,1,0,-1,-1};

void sel(int x,int y){

a[x][y]=2;

int i,tempi,tempj;

for(i=0;i<8;i++){

tempi=x+movex[i];

tempj=y+movey[i];

if(a[tempi][tempj]==1) sel(tempi,tempj);

}

}

int main(void){

int i,j;

int row,col,x,y,c;

while(cin>>row>>col>>x>>y&&!(row==0&&col==0&&x==0&&y==0)){

char* temp=new char[col+1];

for(i=1;i<=row;i++){

cin>>temp;

for(j=1;j<=col;j++){

if(temp[j-1]=='.') a[i][j]=0;

else a[i][j]=1;

}

}

delete []temp;

for(i=0;i<=col+1;i++) a[0][i]=a[row+1][i]=0;

for(i=0;i<=row+1;i++) a[i][0]=a[i][col+1]=0;

sel(x,y);

c=0;

for(i=1;i<=row;i++){

for(j=1;j<=col;j++){

if(a[i][j]!=2) continue;

if(a[i-1][j]==0) c++;

if(a[i+1][j]==0) c++;

if(a[i][j-1]==0) c++;

if(a[i][j+1]==0) c++;

}

}

cout<<c<<endl;

}

return 0;

}