#include <bits/stdc++.h>
using namespace std;
int main(){
  int N, M;
  cin >> N >> M;
  vector<int> A(M);
  for (int i = 0; i < M; i++){
    cin >> A[i];
  }
  vector<long long> m(N + 1);
  for (int i = 1; i <= N; i++){
    m[i] = i;
  }
  for (int i = 1; i <= N; i++){
    for (int j = i * 2; j <= N; j += i){
      m[j] -= m[i];
    }
  }
  vector<long long> g(N + 1, 0);
  for (int i = 1; i <= N; i++){
    for (int j = i; j <= N; j += i){
      g[j] += (j / i) * m[i];
    }
  }
  long long ans = 0;
  for (int i = 0; i < M; i++){
    ans += g[A[i]] - A[i];
  }
  cout << ans << endl;
}