#include <stdio.h>

main() {

char s[50];
char digits[10]={0};

char *p;

scanf("%s",s);
p=s;

while( *p != '\0' ) {
	if (digits[*p -'0'] ==0) {
		putchar(*p);
		digits[*p-'0']++;
	p++;
		}
	else p++;
	}
putchar('\n');
}