# 桃園國中實作 第2題
# 第二題
# 0代表海
# 1代理陸地
# 給一個坐標,若是0,則輸出0
# 若是1,則與他這個陸地相連的土地有幾個
# 輸入
# 4 5(列,行)
# 1 1坐標
# 00000
# 00000
# 00000
# 00000
# 輸出0
# 4 5
# 1 2
# 0 1 1 0 0
# 0 1 1 0 1
# 0 0 1 0 0
# 0 0 0 0 1
# 輸出5
d = '''
4 5
1 2
0 1 1 0 0
0 1 1 0 1
0 0 1 0 0
0 0 0 0 1
'''
d = d.strip().splitlines()
m,n = map(int,d[0].split())
x,y = map(int,d[1].split())
dd = d[2:]
d = []
for i in dd:
t = [ int(j) for j in i.split() ]
d.append(t)
if d[x][y]==0:
print(d[x][y])
else:
rangeList= []
for i in range(m):
for j in range(n):
rangeList.append([i,j])
visitList = []
t = [x,y]
tryList = [t]
while len(tryList)>0:
t = tryList.pop()
visitList.append(t)
tryList = []
for i in [-1,0,1]:
for j in [-1,0,1]:
if [x+i,x+j] in rangeList and not (i !=0 and j!=0) and [x+i,x+j] not in visitList:
tryList.append([x+i,x+j])
for i in tryList:
p,q = i[0],i[1]
if d[p][q]!=0:
d[p][q]=d[p][q]+1
maxList = []
for i in d:
maxList.append(max(i))
print(max(maxList))
# 執行結果
# 5