import math
import sys
def S(): return sys.stdin.readline().rstrip()
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int, sys.stdin.readline().rstrip().split())
def LI(): return list(map(int, sys.stdin.readline().rstrip().split()))
def LS(): return list(sys.stdin.readline().rstrip().split())

ans = 1000
s = S()

for i in range(len(s)):
    if s[i] != "c":
        continue
    cnt = 0
    for j in range(i + 1, len(s)):
        if s[j] == "w":
            cnt += 1
        if cnt == 2:
            ans = min(ans, j - i + 1)
            break

if ans == 1000:
    print(-1)
else:
    print(ans)