# Past Challenges

## leetle

## 10. First Missing Positive

76%

Write a function `solve` that finds the first missing positive integer given an unsorted list. That is, the smallest positive integer not in the list.

**Example:** `Input: [3,4,-1,1]` `Output: 2`

Make sure you `return` your solution, don't print!

```python

def solve(nums):
    pass
```