You climb a staircase of n steps, taking 1 or 2 steps at a time. How many distinct ways can you reach the top?
Input: one line, the integer n.
Output: the number of distinct ways.
2
2
1+1 or 2.
3
3
1+1+1, 1+2, 2+1.
Run your code against the sample tests, or Submit to run the full suite.