from itertools import permutations
def next_smaller(num):
    num = str(num)
    l = len(num)
    cur = num[-1]
    indx = 0
    out = []

    for n in num[::-1]:
        if n <= cur:
            cur = n
            indx +=1
        else:
            break

    res = (num[-indx-1::])
    for var in list(permutations(res)):
        out.append(int(''.join(var)))


    out.sort()
    res = int(res)
    i = out.index(res)
    if i == 0:
        return -1

    else:
        return int(num[:l-indx-1] + str(out[i-1]))