#include <stdio.h>

void printhex(unsigned x)
{
	if( x )
	    printhex(x>>4),putchar("0123456789ABCDEF"[x&15]);
}

int main(void) {
	unsigned u;
	
	if( 1==scanf("%u",&u) )
	{
		if( u==0 )
			puts("0");
		else
			printhex(u);
	}
	return 0;
}