Upper Triangular Matrix Multiplication

Perform matrix multiplication of two upper triangular matrices:

$$C = A \cdot B$$

Where A and B are upper triangular matrices.

The result C will also be an upper triangular matrix.

Input

• Upper triangular matrix $A$ of size $N \times N$
• Upper triangular matrix $B$ of size $N \times N$

Output

• Upper triangular matrix $C$ of size $N \times N$

Notes:

• All matrices $\text{A}$, $\text{B}$, and $\text{C}$ are stored in row-major order.
• A matrix $L$ is upper triangular if $L_{ij} = 0$ for all $i > j$.
• This problem is adapted from KernelBench