import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

S = ''.join(line.rstrip().decode('utf-8') for line in readlines())

answer = 0
for i in range(1,15):
    x = 'o' * i
    if S.find(x) != -1:
        answer = i

print(answer)