|Fox Ciel is playing a game called Addition Game.
Three numbers A, B and C are written on a blackboard, and Ciel initially has 0 points. She repeats the following operation exactly N times: She chooses one of the three numbers on the blackboard. Let X be the chosen number. She gains X points, and if X >= 1, the number X on the blackboard becomes X-1. Otherwise, the number does not change.
Return the maximum number of points she can gain if she plays optimally.
|-||A, B and C will each be between 1 and 50, inclusive.|
|-||N will be between 1 and 150, inclusive.|