try:
    n = list(map(int, input().split()))
except:
    print('Hello World!')
    exit()
if len(n) == 2:
    s = input()
    print(sum(n), s)
    exit()
elif len(n) == 1:
    n = n[0]
    try:
        a = list(map(int, input().split()))
        if len(a) == n:
            print(sum(a))
        else:
            b = [int(input()) for i in range(n - 1)]
            print(sum(a) + sum(b))
    except:
        print(n * (n + 1) // 2)
        exit()