Off topic:basename: extra operand error

Question

[evelyn]

I want to use an array for fastq files:-

RUN=${SLURM_ARRAY_TASK_ID}
R1=$(head -n $RUN input.txt | tail -n 1)
data=$(basename $R1 | cut -f 1 -d'_')

Where, input.txt:

GC-1   9  27
GC-2   7  79
GC-3   2  53
GC-4   6  32

I am getting an error $data: basename: extra operand '27'

I am not sure where is the error. Thank you!