I just submitted my code and it failed at this test case

Input: 4, 3

Output: "1423"

Expected: "1324"

I must have misunderstood the sequence, but I thought the permutation sequence for n = 4 is

```
1234
1243
1423
1324
1342
1432
2134
2143
2413
...
```

Could anyone let me know the correct sequence for n = 4? Thanks.