submit a job to a supercomputer using slurm

edit

I am trying to submit a job to a supercomputer using slurm. The script is as follows

#!/bin/bash

#SBATCH -n 40  
#SBATCH -N 1  
#SBATCH -t 3-0:00  
#SBATCH --mem=64000  
#SBATCH -o myjob.o  
#SBATCH -e myjob.e  
#SBATCH --mail-type=ALL  
#SBATCH --mail-user=aaa@gmail.com  
#SBATCH --gres=gpu:2  

module load sage
sage
load("HPC2.sage")

But it has errors:

sbatch: error: Sending email to aaa@gmail.com for events: 271
sbatch: error: Batch job submission failed: Invalid generic resource (gres) specification

How to fix this problem? Thank you very much.