INF = 1e+9 + 7
ans = INF
s = raw_input()
n = len(s)
for i in xrange(n):
  if s[i] != "c":
    continue
  cnt = 0
  for j in xrange(i+1, n):
    if s[j] == "w":
      cnt += 1
    if cnt == 2:
      break
  if cnt == 2:
    ans = min(ans, j-i+1)

if ans == INF:
  ans = -1
print ans