S = input()
c = S.find('c')
if c == -1:
    print(-1)
else:
    w1 = S.find('w',c+1)
    if w1 == -1:
        print(-1)
    else:
        w2 = S.find('w',w1+1)
        if w2 == -1:
            print(-1)
        else:
            print(w2 - c + 1)