Animating rotation

Greetings,

I hope there is help for this problem.

I need to rotate a cube for the first 50 of 100 frames.

I set 3 keyfrmes.

Key 1 = 0 degrees
Key 2 = 360 degrees
Key 3 = 360 degrees

One would expect that between key1 and key2 there would be rotation and between Key2 and key3 NO rotation.
Unfortunately there is 'over shoot" and the rotation exceed 360 degrees after key2 but returns to 360 degrees at key3.

In the timeline it can be seen that the curve goes beyong 360 between key2 and 3.

How can I fix this so there is no rotation between keys 2 and 3?

Thanks

Greg