CF is a multinational multi player real-time online exciting electronic sports game . Happy , an old retired player , can not extricate himself from being addicted to CF .
The game will hold competitions frequently . After each competition , the rating of the participants in the game will increase or decrease according to their performance .
It's a pity that such competitions are all late at night . Happy's body does not support him to stay up late to play games continuously . Therefore, every time he stays up late to play a game, he needs to rest for at least

days , that is , if he played a game at the

-th day , the next game can only be played at the

-th (

) day .
However, as Happy is a fanatic ,
once he has rested for more than or equal to
days , he will firmly participate in the next game .
Happy is a person with strong desire to win . He saw the game arrangement of CF , and according to the information obtained , he estimated how much his rating would increase or decrease after he participated in the game .
Happy's wife was very resistant to this, so she put forward a request :
Happy can choose any date to start his first game ( we call that CF journey ), then played at most

games . In his CF journey , if Happy wants to give up , he can end his journey at any day .
Please help Happy to calculate the maximum rating he can get .