# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	S = input()
	N = len(S)
	ans = INF
	for i in range(N):
		for j in range(i + 1, N):
			for k in range(j + 1, N):
				if S[i] == "c" and S[j] == "w" and S[k] == "w":
					ans = min(ans, k - i + 1)

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

if __name__ == '__main__':
	main()