Number Pattern 3 by do while loop

Code Box by do while loop
------------------------------
/*program to print number pattern  by do while loop

  1
  22
  333
  4444
  55555

*/

class npat3do
{
public static void main(String a[])
{
int n,i,j;
i=1;
n=Integer.parseInt(a[0]);

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