Stones ngec error

/* package codechef; // don’t place package name! */

import java.util.;
import java.lang.
;
import java.io.*;
class Codechef
{
public static void main (String[] args)
{

         int p,o=0,i,y,z,f;
	Scanner ob=new Scanner (System.in);
   int n=ob.nextInt();
	for(f=0;f<n;f++)
	{
	    String s=ob.next();
	    String j=ob.next();
	    p=0;
	    int l=s.length();
	    int k=j.length();
	    for(y=0;y<l;y++)
	    {
	        char c=s.charAt(y);
	       
	        
	        for(z=0;z<k;z++)
	        {
	            char d=j.charAt(z);
	            
	            if(c==d)
	            p++;
	       }
                   
	        
	    }
	     System.out.println(p);
	    
	    
	    
	
	

	    
	}
	    
	    
	    
	    
	    
	    
	    
	    
	    
	}
	
	
}

This code is giving me NGEC error

Exception in thread “main” java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:862)
at java.util.Scanner.next(Scanner.java:1485)
at java.util.Scanner.nextInt(Scanner.java:2117)
at java.util.Scanner.nextInt(Scanner.java:2076)
at Codechef.main(Main.java:13)