s=gets.chomp.chars.to_a
max=0;c=0
str="";tstr=""
ans=[]
s.each{|e|
    if e=="ｗ"
        c+=1
        if max<c
            max=c
            ans=[tstr]
        elsif max==c
            ans+=[tstr]
        end
        str=""
    else
        c=0
        tstr=str+=e
    end
}
ans.each{|e|
    puts e if !e.empty?
}