S = input().rstrip()
W, X = "", ""
A = []
cnt, MAX = 0, 0
flag = False
for i in range(len(S)):
    if S[i] == "ｗ":
        if flag:
            cnt += 1
            X = W
    else:
        flag = True
        if MAX <= cnt:
            if MAX < cnt:
                A.clear()
            MAX = cnt
            if X != "":
                A.append(X)
        if cnt > 0:
            W = ""
        cnt = 0
        W += S[i]
if MAX <= cnt:
    if MAX < cnt:
        A.clear()
    A.append(X)
for w in A:
    print(w)