#include<bits/stdc++.h>
using namespace std;
const long long MaxN = 1e5 + 5;
long long n,k;
long long p[MaxN];
long long l, r;
map<long long, long long> mp;
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if(fopen("CHP.inp","r"))
    {
        freopen("CHP.inp","r",stdin);
        freopen("CHP.out","w",stdout);
    }
    cin >> n >> k;
    for (long long i=1; i<=n; i++)
    {
        cin >> p[i];
    }
    cin >> l >> r;
    for (long long i=1; i<=n; i++)
    {
        if(p[i]>r)
        {
            continue;
        }
        else if(p[i]>=l&&p[i]<=r)
        {
            long long y= r/p[i];
            for(long long x=1; x<=y; x++)
            {
                mp[p[i]*x]++;
            }
        }
        else
        {
            long long y = l/p[i];
            if(p[i]*y<l)
            {
                y++;
            }
            long long cnt =y;
            while(p[i]*y<=r)
            {
                mp[p[i]*y]++;
                y++;
            }
        }
    }
    long long ans=0;
    for (auto x : mp)
    {
        if(x.second==k)
        {
            ans++;
        }
    }
    cout << ans;

}