B"The Berland University is preparing to celebrate the 256-th anniversary of its founding! A specially appointed Vice Rector for the celebration prepares to decorate the campus. In the center of the campus n ice sculptures were erected. The sculptures are arranged in a circle at equal distances from each other, so they form a regular n-gon. They are numbered in clockwise order with numbers from 1 to n. The site of the University has already conducted a voting that estimated each sculpture's characteristic of ti -- the degree of the sculpture's attractiveness. The values of ti can be positive, negative or zero. When the university rector came to evaluate the work, he said that this might be not the perfect arrangement. He suggested to melt some of the sculptures so that: Help the Vice Rector to analyze the criticism -- find the maximum value of ti sum which can be obtained in this way. It is allowed not to melt any sculptures at all. The sculptures can not be moved. The first input line contains an integer n (3 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x8920000) -- the initial number of sculptures. The second line contains a sequence of integers t1, xe2 x80 x89t2, xe2 x80 x89..., xe2 x80 x89tn, ti -- the degree of the i-th sculpture's attractiveness ( xe2 x80 x89- xe2 x80 x891000 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89ti xe2 x80 x89 xe2 x89 xa4 xe2 x80 x891000). The numbers on the line are separated by spaces. Print the required maximum sum of the sculptures' attractiveness. In the first sample it is best to leave every second sculpture, that is, leave sculptures with attractivenesses: 2, 4, 5 xd0 xb8 3."...