#include <iostream>
#include <cstdio>
#include <iomanip>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <bitset>
#include <stack>
#include <utility>
#include <numeric>
#include <algorithm>
#include <functional>
#include <cctype>
#include <complex>
#include <string>
#include <sstream>
#include <cassert>
using namespace std;

//common
typedef int  i32;
typedef long long i64,ll;
#define BR "\n"

#define ALL(c) (c).begin(),(c).end()
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define EACH(it,o) for(auto it = (o).begin(); it != (o).end(); ++it)
#define IN(l,v,r) ((l)<=(v) && (v)<(r))

typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii;
typedef long long ll; typedef vector<long long> vl; typedef pair<long long,long long> pll; typedef vector<pair<long long,long long> > vpll;
typedef vector<string> vs; typedef long double ld;

//config
#define MODE_DEBUG
//#define INF 1<<30
//#define EPS 1e-8
//const ll MOD =100000007;

//debug
#ifdef NDEBUG
#define DUMP(x)
#define DUMPLN(x)
#define DEBUG(x)
#define DEBUGLN(x)
#define LINE()
#define LINELN()
#define CHECK(exp,act)
#define STOP(e)
#else
#define DUMP(x)  cerr << #x << " = " << (x)
#define DUMPLN(x)  DUMP(x) <<endl
#define DEBUG(x) DUMP(x) << LINE() << " " << __FILE__
#define DEBUGLN(x) DEBUG(x)<<endl
#define LINE()    cerr<< " (L" << __LINE__ << ")"
#define LINELN()    LINE()<<endl
#define CHECK(exp,act)  if(exp!=act){DUMPLN(exp);DEBUGLN(act);}
#define STOP(e)  CHECK(e,true);if(!(e)) exit(1);
#endif

template<class T> inline string toString(const vector<T>& x) {
	stringstream ss;
	REP(i,x.size()){
		if(i!=0)ss<<" ";
		ss<< x[i];
	}
	return ss.str();
}
template<class T> inline string toString(const vector<vector<T> >& map) {
	stringstream ss;
	REP(i,map.size()){
		if(i!=0)ss<<BR;
		ss<< toString(map[i]);
	}
	return ss.str();
}
template<class K,class V>  string toString(map<K,V>& x) {
	string res;stringstream ss;
	for(auto& p:x)ss<< p.first<<":" << p.second<<" ";
	return ss.str();
}

template<typename T,typename V> inline T mod(T v,V MOD){
	return (v%MOD+MOD)%MOD;
}

#define nextInt(n) scanf("%d",&n)
#define nextLong(n) scanf("%lld",&n)
#define nextDouble(n) scanf("%lf",&n)

int INF=1<<28;

template<typename T>T gcd_positive(T a, T b) { return b == 0 ? a : gcd_positive(b,a%b); }
template<typename T>T gcd(T a, T b) { return gcd_positive(abs(a), abs(b)); }
template<typename T>T lcm(T a,T b){return a*b/gcd(a,b);}

class Main{
public:	
	void run(){
		int N,M;cin >> N >> M;

		ll A;cin >> A;REP(i,N-1){ll a;cin >> a; A=gcd(A,a);}
	
		set<ll> ls;

		map<ll,int> as;
		for(ll p=2;p*p<=1e14;p++){
			int c=0;
			while(A%p==0){
				c++;A/=p;
			}
			if(c!=0){
				as[p]=c;ls.insert(p);
			}
		}
		if(A!=1) {
			as[A]=1;
			ls.insert(A);
		}

		map<ll,int> bs;
		REP(i,M){
			ll B;cin >> B;
			for(ll p=2;p*p<=1e14;p++){
				int c=0;
				while(B%p==0){
					c++;B/=p;
				}
				if(c!=0){
					bs[p]=max(bs[p],c);ls.insert(p);
				}
			}
			if(B!=1) {
				bs[B]=max(bs[B],1);
				ls.insert(B);
			}
		}
		ll res =1;
		EACH(it,ls){
			res*=max(as[*it] -bs[*it]+1,0);
		}
		cout << res<<endl;
	}
};
 int main(){
 	cout <<fixed<<setprecision(15);
	ios::sync_with_stdio(false);
 	Main().run();
 	return 0;
 }


Measured memory_bytes: 1204