s = input().split('ｗ')
result = []
maxcnt = 0
cnt = 0
s.reverse()
for v in s:
    if v == '':
        cnt += 1
    else:
        if cnt > 0:
            if maxcnt < cnt:
                result = [v]
                maxcnt = cnt
            elif maxcnt == cnt:
                result.append(v)
        cnt = 1

if len(result) > 0:
    result.reverse()
    for v in result:
        print(v)
else:
    print()