object Main {
  def main(args: Array[String]): Unit = {
    val s = readLine()
    var ans = s.length + 1
    for (i <- 0 to s.length - 1) {
      for (j <- 0 to i - 1) {
        for (k <- 0 to j - 1) {
          if (s(k) == 'c' && s(j) == 'w' && s(i) == 'w' && ans > i - k + 1)
            ans = i - k + 1
        }
      }
    }
    if (ans == s.length + 1) ans = -1
    println(ans)
  }
}