Getting runtime error NZEC: in magicchef problem using java

program is totally working in my system but i am getting NZEC error while sumitting it codechef import java.util.Scanner; public class Main { public static void magic(int a[])

{
    Scanner in = new Scanner(System.in);
    int x;
    x = in.nextInt();
    x=x-1;
    a[x]=1;
    int s;
    s=in.nextInt();
    for(int i=0;i<s;i++)
    {
        int a1,b1;
        a1=in.nextInt();
        b1=in.nextInt();
        a1=a1-1;
        b1=b1-1;
        int temp;
        temp=a[a1];
        a[a1]=a[b1];
        a[b1]=temp;
    }
    for(int i=0;i<a.length;i++)
    {
        if(a[i]==1)
        {   
            System.out.println(i+1);

        }
    }
}
    public static void main(String args[])
    {
        int n;
        Scanner in=new Scanner(System.in);
        int t;
        do
        {   
            System.out.println("Enter t:");
            t=in.nextInt();
        }while(!(t>=1 && t<=100));
        for(int j=0;j<t;j++)
        {
            n=in.nextInt();
            int a[]=new int[n]; 
            for(int i=0;i<n;i++)
            {
                    a[i]=0;
                }
            magic(a);
        }
}

}