def solve_a():
    n = str(input())
    cnt = 0
    flag = False
    for i in range(len(n)):
        if int(n[i]) == 1:
            cnt += 1
            if flag:
                print('no')
                return
        if int(n[i]) == 0:
            flag = True
    if cnt == 2:
        print('yes')
    elif cnt == 1:
        print('no')
    else:
        print('yes')

if __name__ == '__main__':
    solve_a()