How to solve?

An Example M be the plain text message M=0123456789ABCDEF. where M is in hexadecimal (base 16) format. Rewriting M in binary format, we get the 64-bit block of text: - M=00000001001000110100010101100111100010011010101111001101 11101111 - L=00000001001000110100010101100111 - R=10001001101010111100110111101111 The first bit of M is " 0 ". The last bit is " 1 ". We read from left to right. Let K be the hexadecimal key K=133457799BBCDFF1 K=00010011001101000101011101111001100110111011110011011111 11110001 Cipher Text: 85E813540F0AB405