mincww = 999
s = gets
s.length.times do |i|
    next unless s[i] == 'c'
    wcnt = 0
    (i..s.length).each do |j|
        next unless s[j] == 'w'
        wcnt += 1
        mincww = [mincww, j - i + 1].min if wcnt == 2
    end
end
mincww = -1 if mincww == 999
p mincww