#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

int main(){	
	
	int N,M;
	cin>>N>>M;
	
	
	

	vector<long long> temp(N+1,0LL);
	
	for(int i=1;i<=N;i++){
		temp[i] += i;
		for(int j=i*2;j<=N;j+=i){
			temp[j] -= temp[i];
		}
	}
	
	vector<long long> ans(N+1,0);
	
	for(int i=1;i<=N;i++){
		for(int j=i;j<=N;j+=i){
			ans[j] += temp[i] * (j/i);
		}
	}
	
	long long Ans = 0LL;
	
	rep(i,M){
		int A;
		scanf("%d",&A);
		Ans += ans[A] - A;
	}
	
	cout<<Ans<<endl;
	
    return 0;
}