//先dfs搜打掉的球数
//再dfs2搜会掉下来的球数
//注意状态保存和球粘连关系就好了
#include
#include
using namespace std;
int H,W,h,w;
char map[110][110];
bool v[110][110];
char color;
int shoot;
int d[2][6][2] =
{
{{0,-1},{0,1},{-1,0},{-1,1},{1,0},{1,1}},
{{0,-1},{0,1},{-1,0},{-1,-1},{1,0},{1,-1}}
};
void dfs(int x,int y)
{
if(xH)
return ;
if(yW-(x+1)%2)
return ;
if(map[x][y-1] == color)
{
shoot ++;
map[x][y-1] = 'E';
for (int i=0;i dfs( x+d[x%2][i][0], y+d[x%2][i][1] );
}
}
}
bool dfs2(int x,int y)
{
char ch;
if(x if(yW-(x+1)%2 || x>H)
return false;
if(map[x][y-1] == 'E')
return false;
else
{
shoot ++;
ch = map[x][y-1];
map[x][y-1] = 'E';
v[x][y-1] = true;
for (int i=0;i if ( dfs2( x+d[x%2][i][0], y+d[x%2][i][1] ) ) {
map[x][y-1] = ch;
return true;
}
}
}
return false;
}
int main()
{
int i,j,ans,total;
while( scanf("%d %d %d %d",&H,&W,&h,&w)!=EOF )
{
for(i=1;i scanf("%s",map[i]);
memset(v,0,sizeof(v));
color = map[h][w-1];
ans = 0;
shoot = 0;
if (color != 'E') {
dfs(h,w);
if(shoot >= 3) ans += shoot;
else {
printf("0\n");
continue;
}
for (i=1; i for (j=1; j shoot = 0;
if( !v[i][j-1] && map[i][j-1]!='E' && !dfs2(i,j) ) {
ans += shoot;
}
}
}
}
printf("%d\n",ans);
}
return 0;
}