import itertools

def next_largest_number(input_number):
    number = list(map(int, str(input_number)))
    n = set(list(itertools.permutations(number, len(str(input_number)))))
    list_res = []
    for numbers in n:
        res = ''
        for  i in numbers:
            res += str(i)
        if not res.startswith('0'):
            list_res.append(int(res))
    list_res.sort()
    return list_res[list_res.index(input_number) +1]

print(next_largest_number(2134))
print(next_largest_number(1234))
print(next_largest_number(1243))
print(next_largest_number(234765))
print(next_largest_number(19000))