Programing 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 Main.main(Main.java:5)
how can i resolve this error
code is
import java.util.*;
public class Main {
public static void main(String args[]) {
Scanner scn= new Scanner(System.in);
int n= scn.nextInt();

		int nst=1;
		int nzo=1;
		int row=1;
		int val=1;
		while(row<=n)
		{


			int col=1;
		    while(col<=nst)
			{

				 

				System.out.print(val);
				col++;
			}
			if(row>=3)
			{
				for(int i=1;i<=nzo;i++)
				{
					 System.out.print("0");
				}
				nzo++;
			}
			if(row>=2)
			{
				int co=1;
		    while(co<=nst)
			{

				 

				System.out.print(val);
				co++;
			}}

			if(row>=2)
			{
				val++;
			}
				
			row++;
				System.out.println();


		}

    }
}

I have not checked your logic but by seeing the error…this error comes when you try to run your code and you have not provided custom input…so before running your code click on provide custom input…give a value of n and then click on run