the code is not running on codechef can anyone find the error please this is the solution for the Temple Run Problem...

package codechef;

import java.util.*;

public class Codechef {
    
    public static void main(String[] args) {
        int f=0,i,j,k,l;
        Scanner sn=new Scanner(System.in);
        int s=sn.nextInt();
        String q[];
        q=new String[s];
        for(j=1;j<=s;j++)
        {
            int n=sn.nextInt();
            int a[]=new int[n];
            for(k=0;k<n;k++)
                a[k]=sn.nextInt();
            for(i=0;i<n-1;i++)
            {
                if(n%2==0)
                {
                    f=1;break;
                }
                if(i<(n-1)/2)
                {
                   if(a[0]!=1 || (a[i]-a[i+1])!=-1)
                   {f=1;break;}
                }
                 if(i>(n-1)/2)
                {
                   if((a[i]-a[i+1])!=1)
                   {f=1;break;}
                }
            }
            if(f==0)
              q[j-1]="yes";
            else
             q[j-1]="no";
            }   
   for(l=0;l<s;l++)
       System.out.println(q[l]);
   }
    }

Dont make your class public and remove that “package codechef;” . It should execute fine after this.