def maxx(subs):
    al = {}
    for sub in subs:
        for s in sub:
            if not al.has_key(s): al[s] = 1
            else: al[s] += 1
    maxx = max(al.values())
    return filter(lambda item: item[1] == maxx and len(item[0]) > 1, al.iteritems())


def substrs(words):
    al = []
    for word in words:
        subs, ii = [], 0
        for i, char in enumerate(word):
            try:
                if not subs:
                    subs.append(char)
                    if i != 0:
                        ii += 1
                elif (char == word[i - 1]) and (char == word[i + 1]):
                    subs[ii] += char
                else:
                    subs.append(char)
                    ii += 1
            except IndexError:
                subs[ii] += char
        al.append(subs)
    return maxx(al)

if __name__ == '__main__':
    print(substrs(("lkhrfjhfdskhl",
                   "ijgfjlgfjklfg",
                   "ljfjlkfs")))