#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 {
  struct num { 
    ll f, x, n;
    bool operator== (const num &a) const { return f==a.f&&x==a.x&&n==a.n; };
    num  operator+  (const num &a) const { return (num){f+a.f,x+a.x,n+a.n}; };
  };
  vector<num> pfac; num p0;
  Sieve(ll x=pow(10,6)+10) {
    p0 = {-1,0,0};
    pfac.resize(x,p0);
    repr(i,2,x) {
      if (pfac[i]==p0) {
        for (ll j=1; i*j<=x; j++) {
          if (pfac[i*j]==p0) {
            if (j%i==0) pfac[i*j] = pfac[j] + (num){0,1,0};
            else pfac[i*j] = {i,1,j};
          }
        }
      }
    }
  }
  bool isp(ll n) { return pfac[n].f==n; }
  vector<p_ll> factors(ll n) {
    vector<p_ll> result;
    while (n>=2) { 
      result.push_back(make_pair(pfac[n].f,pfac[n].x));
      n=pfac[n].n;
    }
    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 * ((x.first-1)*(x.second+1)+1);
    nowres -= A[i];
    // cout << nowres << endl;
    result += nowres;
  }
  cout << result << endl;
  return 0;
}