Gromacs can't recognize .tpr files in REMD

GROMACS version: 2018.4
GROMACS modification: No
Here post your question

I prepared six .tpr files (prod_0.tpr, prod_1.tpr, prod_2.tpr, prod_3.tpr, prod_4.tpr, prod_5.tpr,) of different temparture in the directory that I ran the following command.

gmx mdrun -deffnm prod_ -table table.xvg -tablep table.xvg -replex 10 

Then it returns the error like this.

Error in user input:
Invalid input values
  In option s
    Required option was not provided, and the default file 'topol' does not
    exist or is not accessible.
    The following extensions were tried to complete the file name:

Is there any idea why it doesn’t recognize .tpr files?
Thanks in advance.

You should use the -multi option. And I don’t think you can combine that with -deffnm.

The -multidir option is nicer though.

Thank you for the answer.
-multidir option worked.