# coding: utf-8
str = gets.chomp
len = str.length
i = 0
while i < len && str[i] == "ｗ" do
    i = i+1
end
str = str[i, len-i]
len = str.length
l = 0
r = 0
maxi = 0
while l < len do
    if str[l] != "ｗ" then
        l = l+1
    else
        r = l
        while r < len && str[r] == "ｗ"
            r = r+1
        end
        maxi = [maxi, r-l].max
        l = r
    end
end
if maxi==0 || len==0 then
    print "\n"
else
    ans = []
    l = 0
    r = 0
    while l < len do
        if (str[l] != "ｗ") then
            m = l
            while m < len && str[m] != "ｗ"
                m = m+1
            end
            r = m
            while r < len && str[r] == "ｗ"
                r = r+1
            end
            if r-m == maxi then
                ans.push(str[l, m-l])
            end
            l = r
        end
    end
    ans.each do |s|
        print s, "\n"
    end
end