Program wont read number from text file

I’m trying to write a script that takes input from a text file, runs the input in a C program and determines if the answer is correct or not. The text file includes the input value and the correct value separated by a comma. The problem is that it’s not working for -20. I think it’s something to do with the – symbol because if I change the text file to have a space in front or remove the – symbol it works. Ill put the C programs, text file and script down below. I also included a sample output. The highlighted lines shouldn’t be there. Thanks in advance!

(nb. I’m not allowed to change the text file as a valid solution)

Output

C programs

#include <stdio.h>
int increment(int a);
void main(void){
        int a;
        scanf("%i", &a);
        a = increment(a);
        printf("%i\n", a);
        return;
}

int increment(int a){
        int b = a;
        b = b + 1;
        return b;
}

Test Input File

1,2
-20,-19
37,38
1.4,2.4
0,1
0.0,1.0
'20','21'
lab04,lab05

Bash Script

#!/bin/bash

:
echo""
echo "start building main program"
echo "start compiling to assembly lines..."
cc main.c -S
cc increment.c -S
echo "translating to op codes"
cc main.s -c
cc increment.s -c
echo "statically linking all required op codes..."
cc main.o increment.c -o main
echo "build successfully done!"
echo "running main program"
echo ""

passedCount=0
failedCount=0

while read input
do
        IFS=,
        set $input
        correctAnswer=($2)
        #runs main with the input of $1 and stores the result in output
        output=$(./main <<< $1)

        if [ $output == $correctAnswer ]; then
                echo "input: $1, main: $output, correct: $correctAnswer ==> passed"
                passedCount=$((passedCount +1))
        fi

        if [ $output != $correctAnswer ]; then
                echo "input: $1, main: $output, correct: $correctAnswer ==> failed"
                failedCount=$((failedCount+1))
        fi

done <"./test_inputs.txt"

echo ""
echo "Total Passed: $passedCount"
echo "Total Failed: $failedCount"

>Solution :

set $input throws an error when $input starts with a dash, because set thinks that it’s a flag. Use set -- $input instead:

--  Assign any remaining arguments to the positional parameters.
    If there are no remaining arguments, the positional parameters
    are unset.

— help set