死活卡不进2s

#include<bits/stdc++.h>
#define N 1000000005
#define int long long
#define ull unsigned long long
using namespace std;
namespace IO{
	template<typename T> inline void write(T x){
		if(x<0) putchar('-'),x=-x;
		if(x==0){
			putchar('0'); return ;
		}
		if(x>9) write(x/10);
		putchar(x%10+'0');
		return ;
	}
	template<typename T> inline void read(T &x){
		x=0; int w=1; char ch=getchar();
		while(!isdigit(ch)){
			if(ch=='-') w=-1; ch=getchar();
		}
		while(isdigit(ch))
			x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
		x*=w; return ;
	}
}
using namespace IO;
ull bs[(N>>6)+5],a[65];
int n,m,ans;
signed main(){
	read(n),read(m);
	for(int i=1,j;i<=m;++i){
		read(j);
		if(j>=64) for(int k=0;k<=n;k+=j) bs[k>>6]|=(1ull<<(k&63));
		else{
			for(int k=0;k<=64;++k) a[k]=0ull;
			for(int k=0;k<=(j<<6);k+=j) a[k>>6]|=(1ull<<(k&63));
//			for(int k=0;k<=(n>>6);k++) bs[k]|=a[k%j];
			for(int k=0;k<=j;++k){
				for(int q=k;q<=(n>>6);q+=j){
					bs[q]|=a[k];
				}
			}
		}
	}
	if((n&63)!=63) bs[n>>6]&=(1ull<<(n+1-((n>>6)<<6)))-1;
	bs[0]&=-2ull;
	for(int i=0;i<=(n>>6)+1;++i){
		ans+=__builtin_popcountll(bs[i]&(bs[i]>>1)&(bs[i]>>2));
		if((bs[i]&(1ull<<62))&&(bs[i]&(1ull<<63))&&(bs[i+1]&1)) ans++;
		if((bs[i+1]&1)&&(bs[i]&(1ull<<63))&&(bs[i+1]&2)) ans++;
	}
	write(ans);
	return 0;
}