s = io.read()
c, w = {}, {}
n = string.len(s)
for i = 1, n do
    a = string.sub(s, i, i)
    if(a == "c") then table.insert(c, i) end
    if(a == "w") then w[i] = true end
end
minlen = 101
for k, v in pairs(c) do
    found = false
    for i = v + 1, n - 1 do
        if(w[i] ~= nil) then
            for j = i + 1, n do
                if(w[j] ~= nil) then
                    minlen = math.min(minlen, j + 1 - v)
                    found = true
                    break
                end
            end
        end
        if(found) then break end
    end
end
if(100 < minlen) then minlen = -1 end
print(minlen)