s=input()+' '
b=''
l=[]
c=max=0
for i in s:
    if i=='ｗ':
        c+=1
    else:
        if c>max and b:
            max=c
            l=[]
        if c==max:
            l+=[b]
        if c>0:
            b=''
            c=0
        b+=i
for i in l:
    print(i)