#Java, 143 141 bytes
interface T{static void main(String[]a)throws Exception{int i=new java.util.Scanner(System.in).nextInt();do System.out.print(i);while(i>0);}} This definitely needs a lot of work.
interface T { static void main(String[] a) throws Exception { int i = new java.util.Scanner(System.in).nextInt(); do { System.out.print(i); } while (i > 0); } }