s = input()

w = 0
t = ''
l = []
for i in s:
    if i != 'ｗ' and w == 0:
        t += i
    elif i == 'ｗ':
        w += 1
    else:
        if t != '':
            l.append([w, t])
        t = i
        w = 0
else:
    l.append([w, t])

l2 = sorted(l)[::-1]
x = l2[0][0]

for i in l:
    if i[0] == x:
        print(i[1])