s = input()
from bisect import bisect_left
C = []
W = []
for i,c in enumerate(s):
    if c=="c":
        C.append(-i)
    elif c=="w":
        W.append(i)
C = C[::-1]
ans = INF = 500
lc,lw = len(C),len(W)
for i in W:
    v = bisect_left(C,-i)
    if v == lc: continue
    w = bisect_left(W,i+1)
    if w == lw: continue
    ans = min(ans,W[w]+C[v]+1)

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