AtCoder Grand Contest1

1

def solve():
    #不难证明答案为排序后的所有奇数项之和。
    n = int(input())
    a = list(map(int,input().split()))
    a.sort()
    ans = sum(i for i in a[0::2])
    print(ans)

solve()

2

'''
观察 模拟 手玩
https://blog.csdn.net/liufengwei1/article/details/109541100
a = n -x
b = x
且规定 a>=b
每次三角形的边长都是短边的边长 然后2次反射后长度就会减少一个b
总共就走减少a/b次长度
'''

def calc(a,b):
    if a < b:
        a,b = b,a
    n = a // b
    if a % b == 0:
        return b * (2 * n - 1)
    else:
        return calc(b,a%b) + 2*b*n

def main():
    n,x = map(int,input().split())
    ans = n + calc(x,n-x)
    print(ans)
main()