# REV2Challenge :![](https://github.com/mali44/CTF-Write-ups/blob/master/2018-03-21-angstromctf/rev_2/rev_2.png?raw=true)
Firstly to be aware of what strings in it I run strings command and check out the flaw. Found that:![](https://github.com/mali44/CTF-Write-ups/blob/master/2018-03-21-angstromctf/rev_2/rev2%20images/rev2_Strings.png?raw=true)I see there are two levels of  reaching the flag out. In this case let go through:yeah just like what hint said I went to radare2 and analyze the main function..
```r2 -d ./rev2_32[0xf7f79c70]> aaaa #analyze all file[0xf7f79c70]> pdf@main```Here is first we need to look:![](https://github.com/mali44/CTF-Write-ups/blob/master/2018-03-21-angstromctf/rev_2/rev2%20images/rev2_radare_main_1.png?raw=true)
Now take attention over here row:```0x08048546      3dd7110000     cmp eax, 0x11d70x0804854b      741e           je 0x804856b```Our first input get compared with 0x11d7. What that mean is in decimal system=  4567If I do enter random one it'd take me through```0x08048554      6834870408     push str.Sorry__your_guess_of__d_was_incorrect._Try_again```So I pass easily to second level. By that mean is we jump to address 0x804856b.Level 2 question is asked as you can see in the image above.We enter second input/S cuz just like in question it want 2 inputs from us
##But A rule there is ! Firstly both of our inputs get controlled if the both are in between 9