s = input()
while s and s[0]=="ｗ": s = s[1:]
res = []
now = ""
c = 0
for i in s:
    if i != "ｗ":
        if c:
            res.append(c)
            c = 0
        now += i
    else:
        if now:
            res.append(now)
            now = ""
        c += 1
if now: res.append(now)
if c: res.append(c)

ans = []
num = 0
for i,j in zip(res[::2],res[1::2]):
    if num < j:
        ans = [i]
        num = j
    elif num==j:
        ans.append(i)
for i in ans:
    print(i)