The easiest way to get to the entrance to call in any apartment. Tell me that you forgot the keys at home, what does not work the lock, I brought the Newspapers or came to change the lightbulbs in the stairwell. As a rule, people do not even have time to listen to your monologue and press the desired button in his apartment.
Fastest way to get to the entrance – come in "rush hour", when most residents returned to work. In this case you will enter along with those who enter or leave the house.
At lunch time to wait for an incoming tenant would be long. Don't just stand there. Look around. It was at this time the greatest number of strolling mothers with children. Some are in wheelchairs right at the entrance. Ask them to open the lock.

If you have the key from the intercom, but it does not work, make sure the key is not demagnetized. If the keys are faulty several people - call the service company. The phone is usually set on the castle. Maybe the intercom was broken. The organization is required to troubleshoot.
Try to leave a spare set of keys to a close relative or a trusted friend. Well, if the person lives in your area. In an emergency situation you can always ask him for help and thus not to remain on the street.