from collections import Counter as C
N, M = map(int, input().split())
A = [int(a) for a in input().split()]
X = [-1] * (N+1)
L = [[] for _ in range(N+1)]
k = 2
while k <= N:
    X[k] = 1
    L[k].append(k)
    for i in range(k*2, N+1, k):
        X[i] = 0
        L[i].append(k)
    d = 2
    while k**d <= N:
        for i in range(k**d, N+1, k**d):
            L[i].append(k)
        d += 1
    while k <= N and X[k] >= 0:
        k += 1
P = [i for i in range(N+1) if X[i] == 1]

def calc(n):
    s = 1
    l = C(L[n])
    for p in l:
        s = s * p ** (l[p] - 1) * ((p - 1) * (l[p] + 1) + 1)
    return s

ans = - sum(A)
for a in A:
    ans += calc(a)
print(ans)