S = input()
c = []
w1 = []
w2 = []

for k in range(len(S)):
    if S[k] == "c":
        c.append(k)

for l in c:
    for m in range(l+1,len(S)):
        if S[m] == "w":
            w1.append(m)

for l in w1:
    for m in range(l+1,len(S)):
        if S[m] == "w":
            w2.append(m)

if len(c) * len(w1) * len(w2) == 0:
    print(-1)
else:
    ans = 100
    for p in c:
        for q in w1:
            for r in w2:
                if p < q < r:
                    ans = min(ans,r-p+1)
    print(ans)