def substrings(s):
    '''
    given a string s,
    generate all substrings of s
    '''
    ss1=[]
    for i in range(len(s1)):
        for j in range(i,len(s1)):
            if s1[i:j+1] not in ss1:
                ss1.append(s1[i:j+1])
    return(ss1)

if __name__ == '__main__':
    import sys
    s1=sys.argv[1]
    s2=sys.argv[2]
    ss1=[]
    for i in range(len(s1)):
        for j in range(i,len(s1)):
            if s1[i:j+1] not in ss1: ss1.append(s1[i:j+1])
            # s1の部分文字列をss1に格納
    ss2=[]
    for k in range(len(s2)):
        for l in range(k,len(s2)):
            if s2[k:l+1] not in ss2: ss2.append(s2[k:l+1])
            # s2の部分文字列をss2に格納
    #   common = [] # 共通部分文字列とその長さを格納
    #for i in ss1:
    #    if i in ss2: common.append((len(i), i))
    common = []
    common.sort() # 長さでソート
    common.reverse() # 長さでソート
    MAX = common[0][0] # 最初の要素(len(i), i)の最初の要素が最大の長さ
    #res = [] # 結果を収める配列
    #for (l, i) in common:
    #    if l == MAX: res.append(i)
    res = []
    print res