s = input()
s += "あ"
t = ""
ans = ""
ans_list = []
maxans = 0
w = 0
status = 0
for i in s:
    if status == 0 and i == "ｗ":
        status = 1
        w = 1
    elif status == 0 and i != "ｗ":
        t += i
    elif status == 1 and i == "ｗ":
        w += 1
    elif status == 1 and i != "ｗ":
        status = 0
        if t != "":
            ans_list.append((w, t))
        t = i

if ans_list == []:
    print("")
else:
    for i in ans_list:
        maxans = max(maxans, i[0])
    for i in ans_list:
        if maxans == i[0]:
            print(i[1])