from collections import defaultdict
def solve():
    S = input()
    if "ｗ" not in S or len(set(S)) == 1:
        return []
    S += '_'
    m = defaultdict(list)
    s = ""
    cnt = 0
    flg = True
    for a in S[::-1] + "ｗ":
        if flg:
            if a == "ｗ":
                cnt += 1
            else:
                flg = False
                s = a
        else:
            if a == "ｗ":
                flg = True
                m[cnt] += [s[::-1]]
                cnt = 1
            else:
                s += a
    return max(m.items())[1]
w = solve()
if w == []:
    print("")
else:
    print(*w, sep="\n")