If you entered the given address you saw a form where you can enter a file name and the content for the file.But this form wasnt really important for this challenge. When you upload a file you get redirected to ```http://host/myfirstweb/index.php?op=view&file=filename```
The first thing i tried was to test if we can open the 'flag.txt' file directry with ```http://host/myfirstweb/index.php?op=view&file=./flag.txt```But the site refuses with "Found flag format in content, no flag for you!"
I tried to enter the flag file directly withhttp://host/flag.txt
and here we go
`Flag: BAMBOOFOX{0hhh_n0_s7up1d_li77l3_8ug}`