# leetle

## 25. Climbing Stairs

Write a function `solve` that calculates how many distinct ways you can climb a staircase of n steps, taking 1 or 2 steps at a time.

**Example:**
`Input: 3`
`Output: 3` (1+1+1, 1+2, 2+1)

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

```python

def solve(n):
    pass
```