sequence = '112222555555444'

max_len = -1
tmp_len = 0
end_index = 0
prew_value = -1

for index, value in enumerate(sequence):
	if value != prew_value:
		if tmp_len > max_len:
			max_len = tmp_len
			end_index = index
		tmp_len = 1
		prew_value = value
	else:
		tmp_len += 1
		
print ("{} from {} to {}".format(sequence[end_index - max_len: end_index],  end_index - max_len, end_index))