Да и нет
The words for yes and no have slightly different meanings in Russian and English. In Russian да means "Yes, you are right", and нет means "No, you are wrong".
As a result the Russians often say yes when we would say no, and vice versa.
This can lead to confusion. Imagine a conversation between Khruschev and Kennedy during the Cuban Missile Crisis.
Kennedy: Nikita, you are not going to press the button, are you?
He was going to say "Yes Mister President, I am not", but it was too late, Kennedy had already pressed his button!