import sys

S = str(input())

result = sys.maxsize
for i, s in enumerate(S):
    if s == 'c':
        _f = S[i + 1:].find('w')
        _s = S[i + _f + 2:].find('w')
        if _f >= 0 and _s >= 0 and result > (_f + _s + 3):
            result = (_f + _s + 3)
print(result if result != sys.maxsize else - 1)