Skobki

s = input()

st = []
pairs = {
    '(': ')',
    '[': ']',
    '{': '}',
}
res = True

for i in range(len(s)):
    if s[i] in pairs:
        st.append(s[i])
    elif st and pairs[st[-1]] == s[i]:
        st.pop()
    else:
        res = False
        break

if res and not st:
    print('yes')
else:
    print('no')