#include <fstream>

using namespace std;
ifstream cin("divk.in");
ofstream cout("divk.out");
#define ll long long
ll v[100001],vs[500001];
int main()
{
    ll n,k,a,b,i,x,rez=0;
    cin>>n>>k>>a>>b;
    for(i=1;i<=n;i++)
    {
        cin>>x;
        vs[i]=vs[i-1]+x;
        vs[i]%=k;
    }
    for(i=a;i<=n;i++)
    {
        v[vs[i-a]]++;
        if(i>b)
            v[vs[i-b-1]]--;
        rez+=v[vs[i]];
    }
    cout<<rez;
    return 0;
}