S = input()
min_cww = 200
cww_size = 200

for i in range(len(S) - 2):
    c = 0
    if S[i] == "c":
        for j in range(i, len(S)):

            if S[j] == "w" and c == 1:
                cww_size = j - i + 1
                break
                
            if S[j] == "w" and c == 0:
                c += 1

    if min_cww > cww_size:
        min_cww = cww_size
        
print(min_cww if min_cww != 200 else -1)