Number Pattern 7 by do while loop

Code Box by do while loop
---------------------------
/*program to print star pattern square box by do while loop

  1
  21
  321
  4321
  54321

*/

class npat7do
{
public static void main(String a[])
{
int n,i,j;
i=1;
n=Integer.parseInt(a[0]);

do
{j=i;
        do
        {
        System.out.print(j);
        j--;
}
while(j>=1);
System.out.print("\n");
i++;
}
while(i<=n);
}


}