1. Encode the input to binary using UTF-8 and append a single '1' to it.

2. Prepend that binary to the message block.

3. Append the original message length (0, 0 in decimal) at the end of the message block as a 64-bit big-endian integer.

4. Add 447 zeros between the encoded message and the length integer so that the message block is a multiple of 512. In this case 0 + 1 + 447 + 64 = 512