#include <stdio.h>

int len(char *s)
{
    int ans = 0;
    while (*s != 0)
        s++, ans++;
    return ans;
}
int main()
{
    char s[100], t[100];
    scanf("%s%s", s, t);
    int n = len(s), m = len(t), min;
    if (n > m)
        min = n;
    else
        min = m;
    for (int ans = min; ans > 0; ans--)
        for (int i = 0; i + ans <= n; i++)
            for (int j = 0; j + ans <= m; j++)
            {
                int isSubstr = 1;
                for (int k = 0; k < ans; k++)
                {
                    if (s[i + k] != t[j + k])
                        isSubstr = 0;
                }
                if (isSubstr == 1)
                {
                    for (int k = 0; k < ans; k++)
                        printf("%c", s[i + k]);
                    return 0;
                }
            }
}