Use GDB and set RIP to flag function.

```
gdb patches
b main
r
info function
set $rip=<print_flag function address here>
c
```

`nactf{unl0ck_s3cr3t_funct10n4l1ty_w1th_b1n4ry_p4tch1ng_L9fcKhyPupGVfCMZ}`