#include<stdio.h>
#include<stdlib.h>
void remove_element(int array[],int position,long int *n){
    int i;
    for(i=position;i<=(*n)-1;i++){
        array[i]=array[i+1];
    }
    *n=*n-1;
}
int main(){
    int k;
    long int n;
    scanf("%ld",&n);
    scanf("%d",&k);
    int *array=malloc(n*sizeof(int));
    int i,j;
    for(i=0;i<n;i++)
        scanf("%d",&array[i]);
    for(i=n-1;i>=0;i--){
        int counter=0;
        for(j=n-1;j>=0;j--){
            if((i!=j)&&(array[i]+array[j])%k==0)
            {
                remove_element(array,j,&n);
                j--;
                continue;
            }
            else if((i!=j)&&(array[i]+array[j])%k!=0){
                counter++;
        }
        }

        if(counter==n-1){
            printf("%ld",n);
            break;
        }
    }
    return 0;
}


I only get about 4 test cases right from 20 test cases.