#!/usr/bin/env python3
#fileencoding: utf-8

def forward(S):
    mi = 100
    count = 0
    start = 0
    mi_start = -1
    mi_end = -1
    w_cnt = 0
    for idx,i in enumerate(S):
        if count == 0 and i == "c":
            count += 1
            start = idx
        elif count >= 1 and i == "w":
            w_cnt += 1
            count += 1
            if w_cnt >= 2:
                if mi > count:
                    mi = count
                    mi_start = start
                    mi_end = idx+1
                count = 0
                w_cnt = 0
        else:
            if count >= 1:
                count += 1
            else:
                count = 0
    return mi,mi_start,mi_end

def backward(s):
    count = 0
    w_cnt = 0
    mi = 100
    mi_start = -1
    mi_end = -1
    start = 0
    for idx, i in enumerate(s[::-1]):
        if i == "w":
            count += 1
            w_cnt += 1
            if w_cnt == 1:
                start = idx
        elif w_cnt >= 2 and i == "c":
            cww = True
            count += 1
            if mi > count:
                mi = count
                mi_start = start
                mi_end = idx+1
            count = 0
            w_cnt = 0
        else:
            if count >= 1:
                count += 1
            else:
                count = 0
    return mi, mi_start, mi_end

S = input()
mi_f, mi_f_start, mi_f_end = forward(S)
if mi_f_start == -1:
    print(-1)
else:
    mi_b, mi_b_start, mi_b_end = backward(S)
    l = len(S)
    if mi_f > mi_b:
        mi_f, mi_f_start, mi_f_end = forward(S[l-mi_b_end:l-mi_b_start+1])
        print(mi_f)
    else:
        mi_b, mi_b_start, mi_b_end = backward(S[mi_f_start:mi_f_end])
        print(mi_b)