Run the commands to redirect the output of the run program to the data.txt file, and then find terms matching with pwn.college in that file,
$ /challenge/run > /tmp/data.txt
$ grep pwn.college /tmp/data.txt
We get the flag pwn.college{Y9YL_tveHaLZ4DwgaQTYv4xFBTw.dhTM4QDL3kTO0czW}