#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<ll, ll> p_ll;

template<class T>
void debug(T itr1, T itr2) { auto now = itr1; while(now<itr2) { cout << *now << " "; now++; } cout << endl; }
#define repr(i,from,to) for (ll i=(ll)from; i<(ll)to; i++)
#define all(vec) vec.begin(), vec.end()
#define rep(i,N) repr(i,0,N)
#define per(i,N) for (int i=(int)N-1; i>=0; i--)

const ll MOD = pow(10,9)+7;
const ll LLINF = pow(2,61)-1;
const int INF = pow(2,30)-1;

vector<ll> fac;
void c_fac(int x=pow(10,6)+10) { fac.resize(x,true); rep(i,x) fac[i] = i ? (fac[i-1]*i)%MOD : 1; }
ll modpow(ll x, ll p) { ll result = 1, now = 1, pm = x; while (now<=p) { if (p&now) { result = result * pm % MOD; } now*=2; pm = pm*pm % MOD; } return result; }
ll inv(ll a, ll m=MOD) { ll b = m, x = 1, y = 0; while (b!=0) { int d = a/b; a -= b*d; swap(a,b); x -= y*d; swap(x,y); } return (x+m)%m; }
ll nck(ll n, ll k) { return fac[n]*inv(fac[k]*fac[n-k]%MOD)%MOD; }
ll gcd(ll a, ll b) { if (a<b) swap(a,b); return b==0 ? a : gcd(b, a%b); }
ll lcm(ll a, ll b) { return a/gcd(a,b)*b; }

// ----------------------------------------------------------------------
// ----------------------------------------------------------------------

struct Sieve {
  vector<ll> pfac;
  Sieve(ll x=pow(10,6)+10) {
    pfac.resize(x,-1); pfac[0] = 0; pfac[1] = 1;
    for (ll i=2; i*i<=x; i++) {
      if (pfac[i]==-1) {
        for (ll j=2; i*j<=x; j++) {
          if (pfac[i*j]==-1) pfac[i*j] = i;
        }
      }
    }
  }
  bool isp(ll n) { return pfac[n]==-1; }
  vector<p_ll> factors(ll n) {
    vector<p_ll> result;
    ll nf = 0, nc = 0;
    while (!isp(n)) { 
      if (nf!=pfac[n]) {
        if (nf) result.push_back(make_pair(nf,nc));
        nf = pfac[n]; nc = 1;
      }
      else nc++;
      n /= pfac[n];
    }
    if (nf!=n) {
      if (nf) result.push_back(make_pair(nf, nc));
      result.push_back(make_pair(n,1));
    }
    else {
      nc++;
      result.push_back(make_pair(nf, nc));
    }
    return result;
  }
};

// ----------------------------------------------------------------------
// ----------------------------------------------------------------------

int main() {
  ll N, M; cin >> N >> M;
  ll A[M]; rep(i,M) cin >> A[i];

  // rep(i,M) {
  //   ll result = 0;
  //   repr(j,1,A[i]+1) result += gcd(A[i],j) - 1;
  //   cout << result << endl;
  // }

  Sieve s;
  ll result = 0;
  rep(i,M) {
    vector<p_ll> factors = s.factors(A[i]);
    ll nowres = A[i];
    // for (auto x: factors) cout << x.first << "^" << x.second << " "; cout << endl;
    for (auto x: factors) nowres = nowres * ((x.first-1)*(x.second+1)+1)/x.first;
    nowres -= A[i];
    // cout << nowres << endl;
    result += nowres;
  }
  cout << result << endl;
  return 0;
}