# AES S-box input and output question

I am new to cryptography. I am looking to understand how to answer this question from my class:

Find below the S-box of AES. Given the input 01010011 in binary, calculate the output.

• be aware that is not the AES s-box, but rather the inverse s-box – Richie Frame Feb 27 '18 at 4:26

Here the S-box is represented by a 2D array. If your input is $01010011$, you have to get it's hexadecimal representation : $0x53$ (because an hexadecimal is represented by four bits, $0101 = 5$ and $0011 = 3$).
Now you only have to get the corresponding output of the Sbox ($5$ is the left nibble, en $3$ the right nibble).
Since $0011$ is your right nibble and $0101$ is your left nibble, row 5 and column 3 give the output of 50 (hex) or $01010000$ in binary.