S = input()


def change2list(S):
    leng = len(S)
    Slist = [0 for i in range(leng)]
    for i in range(len(Slist)):
        Slist[i] = S[i]
    return Slist
change2list

Slist = change2list(S)

def solve(Slist):
    minlen = 101
    for i in range(len(Slist)):
        if Slist[i] == "c":
            for j in range((i+1), len(Slist)):
                if Slist[j] == "w":
                    for k in range((j+1), len(Slist)):
                        if Slist[k] == "w":
                            if (k-i+1) < minlen:
                                minlen = k - i + 1
    if minlen == 101:
        return -1
    else:
        return minlen
solve

minlen = solve(Slist)
print(minlen)