"""以下の場合のようなものが落ちるはず
3 3
xox
ooo
xox
"""

N, M = map(int, input().split())
ans1 = 0
end1 = set()
S = [input() for _ in range(N)]
for i in range(M):
	C = []
	for j in range(N):
		if S[j][i] == "o":
			C.append(j)
	
	if len(C) == 1 and C[0] not in end1:
		end1.add(C[0])
		ans1 += 1
	else:
	    for c in C:
	        end1.add(c)

ans2 = 0
end2 = set()
for i in range(M-1, -1, -1):
	C = []
	for j in range(N):
		if S[j][i] == "o":
			C.append(j)
	
	if len(C) == 1 and C[0] not in end2:
		end2.add(C[0])
		ans2 += 1
	else:
	    for c in C:
	        end2.add(c)

print(min(ans1, ans2))