import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
import time
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines

S=readline().rstrip()
N=len(S)
inf=1<<30
ans=inf
for i in range(N):
    for j in range(i+1,N+1):
        wwc=list("wwc")
        for s in S[i:j]:
            if wwc and s==wwc[-1]:
                wwc.pop()
        if not wwc:
            ans=min(ans,j-i)
if ans==inf:
    ans=-1
print(ans)