def ind(b,n):
    res=0
    while n%b==0:
        res+=1
        n//=b
    return res

def eratosthenes(n):
    spf = [0 for i in range(n+1)]
    for i in range(2,n+1):
        if not spf[i]:
            for j in range(1,n//i+1):
                spf[i*j] = i
    return spf

#spf = eratosthenes(10**6)

def euler_phi(n):
    phi = [1 for i in range(n+1)]
    for i in range(2,n+1):
        if phi[i] == 1:
            for j in range(1,n//i+1):
                e = ind(i,i*j)
                phi[i*j] *= pow(i,e-1)*(i-1)
    return phi

phi = euler_phi(10**6)

N,M = map(int,input().split())
A = list(map(int,input().split()))
data = [0 for i in range(10**6+1)]
for a in A:
    data[a] += 1

res = - sum(A)
for i in range(1,10**6+1):
    for j in range(1,10**6//i+1):
        if data[i*j]:
            res += (i)*phi[j]*data[i*j]

print(res)