//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<n; ++i)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
using namespace std;
using ll = int64_t;
using ld = long double;
using P = pair<int, int>;
using vs = vector<string>;
using vi = vector<int>;
using vvi = vector<vi>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQG = priority_queue<T, vector<T>, greater<T> >;
const int INF = 0xccccccc;
const ll LINF = 0xcccccccccccccccLL;
template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true);}
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true);}
template<typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second;}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << ' ' << p.second;}

struct Sieve {
	int n;
	vector<int> f, primes;
	Sieve(int n=1):n(n), f(n+1) {
		f[0] = f[1] = -1;
		for(int i=2; i<=n; ++i) {
			if(!f[i]) {
				primes.emplace_back(i);
				f[i] = i;
			}
			for(int p:primes) {
				int u = p*i;
				if(u > n or p > f[i]) break;
				f[u] = p;
			}
		}
	}
	//素数判定
	bool isPrime(int x) {return f[x] == x;}
	//素数判定(1つ用)(宣言はsqrt(x)のサイズで)
	bool isPrime1(int64_t x) {
		bool m = true;
		for(int z:primes) {
			if(!(x%z)) {
				m = false;
				break;
			}
		}
		return m;
	}
	//素数列挙
	vector<int > factorList(int x) {
		assert(x <= n);
		vector<int> res;
		while(x != 1) {
			res.emplace_back(f[x]);
			x /= f[x];
		}
		return res;
	}
	//素因数分解　pair(素数, 素因数の数)
	vector<pair<int, int> > factor(int x) {
		vector<int> fl = factorList(x);
		if(fl.size() == 0) return {};
		vector<pair<int, int> > res(1, pair<int, int>(fl[0], 0));
		for(int p : fl) {
			if(res.back().first == p) {
				++res.back().second;
			} else {
				res.emplace_back(p, 1);
			}
		}
		return res;
	}
	//素数列挙(1つ用)(宣言はsqrt(x)のサイズで)
	vector<int64_t> factorList1(int64_t x) {
		vector<int64_t> vec;
		for(int z:primes) {
			while(!(x%z)) {
				vec.emplace_back(z);
				x /= z;
			}
		}
		if(x != 1) vec.emplace_back(x);
		return vec;
	}
	//素数列挙(1つ用)(宣言はsqrt(x)のサイズで)　pair(素数, 素因数の数)
	vector<pair<int64_t, int> > factor1(int64_t x) {
		vector<int64_t> vec = factorList1(x);
		vector<pair<int64_t, int> > vecc;
		for(vector<int64_t>::iterator itr = vec.begin(); itr != vec.end(); ++itr) {
			if(itr != vec.begin() && *itr == *(itr-1)) {
				(vecc.end()-1)->second++;
			} else {
				vecc.emplace_back(pair<int64_t, int>(*itr, 1));
			}
		}
		return vecc;
	}
	//約数列挙
	vector<int> div(int x) {
		vector<int> res(1, 1);
		vector<pair<int, int> > fac = factor(x);
		for(int i = 0; i < int(fac.size()); ++i) {
			int si = res.size();
			for(int j = 0; j < fac[i].second; ++j) {
				for(int k = 0; k < si; ++k) {
					res.emplace_back(res[k+j*si]*fac[i].first);
				}
			}
		}
		sort(res.begin(), res.end());
		return res;
	}
} pp(1000000);

//head



int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	ll ans = 0;
	vi phi(n+1);
	for(int i = 1; i <= n; i++) {
		int &u = phi[i] = i;
		auto f = pp.factor(i);
		for(P x:f) {
			u /= x.first;
			u *= x.first-1;
		}
	}
	vector<ll> sup(n+1, -1);
	rep(i, m) {
		int a;
		cin >> a;
		ans -= a;
		if(sup[a] != -1) {
			ans += sup[a];
			continue;
		}
		auto div = pp.div(a);
		ll &z = sup[a] = 0;
		for(int d:div) {
			z += ll(d)*phi[a/d];
		}
		ans += z;
	}
	cout << ans << endl;
}