Did I misunderstand the question? Can anybody explain more clearly?

```
124575
[72,10]
```

Leetcode gives out answer: 1299

```
124575
[7,210]
```

Leetcode gives out answer: 1271

```
124575
[7210]
```

Leetcode gives out answer: 536

Should't all three return the same result: 536? (by concatenating all digits together in b)