#include <bits/stdc++.h>
using namespace std;

ifstream fin("pairs.in");
ofstream fout("pairs.out");

int main() {
    int n; fin >> n;
    vector<int> prm(n);
    vector<bool> chr(1e6 + 1);
    for (int i = 0; i < n; i++) {
        fin >> prm[i];
        chr[prm[i]] = true;
    }

    vector<bool> sieve(1e6 + 1);
    vector<vector<int>> div(1e6 + 1);
    for (int i = 2; i <= 1e6; i++)
        if (!sieve[i]) {
            if (chr[i])
                div[i].push_back(i);
            for (int j = 2 * i; j <= 1e6; j += i) {
                sieve[j] = true;
                if (chr[j])
                    div[j].push_back(i);
            }
        }

    return 0;

    vector<int> frq(1e6 + 1);
    for (int i = 0; i < n; i++) {
        for (int mask = 1; mask < (1 << div[prm[i]].size()); mask++) {
            int prd = 1, cnt = 0;
            for (int bit = 0; bit < (int) div[prm[i]].size(); bit++)
                if (mask & (1 << bit)) {
                    prd *= div[prm[i]][bit];
                    cnt++;
                }
            frq[prd] += (cnt % 2 ? +1 : -1);
        }
    }

    vector<int> dp(1e6 + 1, n - chr[1]);
    for (int i = 2; i <= 1e6; i++)
        for (int j = i; j <= 1e6; j += i)
            dp[j] -= frq[i];

    int64_t sol = 0;
    for (int i = 0; i < n; i++)
        sol += dp[prm[i]];
    fout << sol / 2 + chr[1] * n << '\n';

    fout.close();
    return 0;
}