Problem Link - Easy Tiling

### Problem Statement

We wish to tile a grid of size N * 2 using 2*1 dominoes (either vertically or horizontally). The task is to find the number of distinct ways to tile the grid, and output the result **mod 10^9 + 7**.

### Approach

The problem is equivalent to finding the (N+1) th Fibonacci number. The reasoning is:

- For an N*2 grid, you can either place a vertical domino (leaving an (N-1)*2 grid) or two horizontal dominoes (leaving an (N-2)*2 grid).

To solve efficiently, we use **matrix exponentiation** to compute Fibonacci numbers. The transformation matrix:

is raised to the power of **N-1** using **binary exponentiation**, making it more efficient with **O(log N)** time.

### Time Complexity

The time complexity is **O(log N)** due to matrix exponentiation.

### Space Complexity

The space complexity is **O(1)** apart from input/output storage.