#include <stdio.h>

int main()
{
    int num, a;
    int count[10] = {0};

    scanf("%d", &num);
    while (num > 0)
    {
        a = num % 10;
        if (!count[a])
        {
            count[a] = 1;
            printf("%d", a);
        }
        num /= 10;
    }
    return 0;
}