//program to print the similar characters in two strings
#include<stdio.h>
int main ()
{
	int i,j,a[i],b[j];
	char str1,str2;
	scanf("%c",&str1);
	scanf("%c",&str2);
	a[i]=strlen(str1);
	b[i]=strlen(str2);
	for(i=0;str1!=0;i++)
		for(j=0;b[j]!=0;j++)
			if(a[i]==b[j])
			printf("%c",a[i]);
}