S = input()
min_cww = 200
cww_size = 200

def search_ww(i, start, c):
    
    if i < len(S):
        
        if S[i] == "w" and c == 0:
            c += 1
            return search_ww(i + 1, start, c)

        if S[i] == "w" and c == 1:
            return i - start + 1

        return search_ww(i + 1, start, c)

    else:
        return 1000

for x in range(len(S) - 2):
    if S[x] == "c":
        cww_size = search_ww(x, x, 0)
        
    if min_cww > cww_size:
        min_cww = cww_size
        
print(min_cww if min_cww != 200 else -1)