#include <iostream>
#include <fstream>
#include <typeinfo>
#include <vector>
#include <stack>
#include <cmath>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <cstdio>
#include <queue>
#include <iomanip>
#include <cctype>
#include <random>
#define syosu(x) fixed<<setprecision(x)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef pair<double,double> pdd;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<P> vp;
typedef vector<vp> vvp;
typedef vector<pll> vpll;
typedef pair<int,P> pip;
typedef vector<pip> vip;
const int inf=1<<29;
const ll INF=1ll<<60;
const double pi=acos(-1);
const double eps=1e-8;
const ll mod=1e9+7;
const int dx[4]={0,1,0,-1},dy[4]={1,0,-1,-0};
const int DX[8]={-1,-1,-1,0,1,1,1,0},DY[8]={1,0,-1,-1,-1,0,1,1};

ll gcd(ll a,ll b){
	if(!b) return a;
	return gcd(b,a%b);
}

ll lcm(ll a,ll b){
	return a/gcd(a,b)*b;
}

ll n,l,h;
vl c;

ll f(ll x){
	ll res=0;
	for(int i=0;i<1<<n;i++){
		ll tmp=1,num=0;
		for(int j=0;j<n;j++) if((i>>j)&1){
			tmp=lcm(tmp,c[j]);
			num++;
			if(tmp>x) break;
		}
		if(num%2==1) res+=x/tmp*num;
		else res-=x/tmp*num;
	}
	return res;
}

int main(){
	cin>>n>>l>>h;
	if(n<1||n>10||l>h||l<1||h>1000000000){
		cout<<-1<<endl;
		return 0;
	}
	c=vl(n);
	for(int i=0;i<n;i++){
		cin>>c[i];
		if(c[i]<1||c[i]>1000000000){
			cout<<-1<<endl;
			return 0;
		}
	}
	sort(c.begin(),c.end());
	c.erase(unique(c.begin(),c.end()),c.end());
	if(c.size()!=n){
		cout<<-1<<endl;
		return 0;
	}
	cout<<f(h)-f(l-1)<<endl;
}