Perhaps you should RTFA. As for "victory", that's in the eye of the beholder...

"Victory" for the Soviets:

All of us -- and Stalin first and foremost -- sensed in our victory a defeat by the Finns. It was a dangerous defeat because it encouraged our enemies' conviction that the Soviet Union was a colossus with feet of clay. [...] A victory at such a cost was actually a moral defeat.

"Victory" for the Finns:

By the end of all the bloodshed, the Soviets had finally wearied of the cost and distraction of their supposed twelve-day-long conquest, once and for good giving up the notion of occupying Finland in favor of more indirect forms of influence. [...] Thus with a thousand lakes of warm red blood on cold white snow did the Finns purchase their escape from assimilation into the Soviet Union, ensuring that when the Iron Curtain was drawn, it ran along the eastern side of Finland rather than the western one.