#include <stdio.h>

int main() 
{
    char str1[100] ={0};
    char str2[100] = {0};
    gets(str1);
    gets(str2);

    char * s1 = str1;
    char * s2  = str2;
    while(*s1)
    {
        s2 = str2;
        while(*s2)
        {
            if(*s2 == *s1)
                break;
            s2++;
        }
        if(*s2 == '\0')
            printf("%c",*s1);
        
        s1++;
    }

    return 0;
}