import sys
from bisect import bisect_right

sys.setrecursionlimit(10 ** 7)
input = sys.stdin.readline
f_inf = float('inf')
MOD = 10 ** 9 + 7


def solve():
    n = int(input())
    A = list(map(int, input().split()))
    A.sort()

    res = 0
    for i in range(n):
        j = bisect_right(A, A[i])
        res += (A[i] + 1) * (j - i - 1)
        k = bisect_right(A, A[i] + 1)
        res += (A[i] + 2) * (k - j)
        res += (A[i] + 1) * (n - k)
    print(res)
    

if __name__ == '__main__':
    solve()