#include<bits/stdc++.h>
using namespace std;
#define ii pair <int, int>
#define app push_back
#define all(a) a.begin(), a.end()
#define bp __builtin_popcountll
#define ll long long
#define mp make_pair
#define f first
#define s second
#define Time (double)clock()/CLOCKS_PER_SEC
#define debug(x) std::cout << #x << ": " << x << '\n';

const int N = 1e6+7;
int pw[N];
bool p[N];
vector <int> d[N];

bool used[N];
int me[N];

int cnt[N];

signed main() {
    #ifdef HOME
    freopen("input.txt", "r", stdin);
    #else
    #define endl '\n'
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cout.setf(ios::fixed); cout.precision(20); 
    #endif

    for (int i = 1; i < N; ++i)
        for (int j = i; j < N; j += i)
            d[j].app(i);
    for (int i = 2; i < N; ++i)
        p[i] = 1;
    for (int i = 2; i < N; ++i) {
        if (p[i]) {
            pw[i] = 1;
            for (int j = i * 2; j < N; j += i) {
                p[j] = 0;
                pw[j]++;
            }   
        }
    }                       

    for (int i = 0; i < N; ++i) {
        reverse(all(d[i]));
    }   

    int n, m;
    cin >> n >> m;
    ll ans = 0;
    for (int i = 0; i < m; ++i) {
        int x;
        cin >> x;

        if (used[x]) {
            ans += me[x];
            continue;
        }   

        used[x] = 1;
        for (int a : d[x])
            cnt[a] = 0;
        for (int a : d[x]) {
            cnt[a] += x/a;
            me[x] += cnt[a] * ((x - 1) % a);
            for (int b : d[a])
                if (b < a)
                    cnt[b] -= cnt[a];
        }   
        ans += me[x];
    }   
    cout << ans << endl;

    #ifdef HOME
    cout << Time << endl;
    #endif
}