<span>I realise that:1. They split the big string into 2 small</span>er strings (add a character '\x01' if the length is odd)<span>2. They reversed these 2 strings.3. They split 2 strings into 2*2 = 4 smaler string </span><span>(add a character '\x01' if the length is odd)4. They reversed these 4 strings......Repeat until all strings have only 1 character....They join them together and delete 'x01' </span><span>characters.So I input a string have the same length as "the output" so I will which position the 'x01' </span><span>characters were and put them into "the .output".Finally, I input that string into the code and have the flags.My code in Python: https://github.com/phamhuudanh96/CTF_WriteUp/blob/master/ctfx_2016_lambda.pyP/s: this is the first time I add writeup. :D If there is sth wrong, pls email me: [email protected]</span>