/*This Program transfers integers to string by inverse
written by Sadi Evren SEKER */

#include <stdio.h>
#include <stdlib.h>

char *itoa(int i, int radix);

main()
{
/*-----Declerations------*/

	int a,b;
	char *c,*d;

/*-----Main Body of program-----*/

	scanf("%d",&a);
	c=itoa(a,4);
	printf("%s",c);
}


char *itoa(int i, int r)
{

/*-----Evereything is done here------*/

	char *b;
	int j,k;
	for(k=0;k<r;k++)
	{
		j=i%10;
		i=i/10;
		b[k]=j+48;
	}
	return b;
}