S = input()

def solve(S):
    if S.count('c') == 0 or S.count('w') < 2:
        return -1
    n = len(S)
    record = float('inf')
    for head in range(n):
        for tail in range(head + 1, n + 1):
            if has_chiwawa(S[head:tail]):
                if tail - head < record:
                    record = tail - head
    if record == float('inf'):
        return -1
    return record

def has_chiwawa(S):
    c = 0
    w = 0
    for s in S:
        if s == 'c' and c == 0:
            c += 1
        if c and s == 'w':
            w += 1
    return w >= 2

print(solve(S))