#include <iostream>
#include <fstream>
#include <algorithm>
#include <iomanip>
#include <cmath>
#include <map>
#include <vector>
#define punct pair<int,int>

#define eps 0.0000000000001
#define MOD 1000000007

using namespace std;

ifstream f("divk.in");
ofstream g("divk.out");
int v[500001];
int fv[100001],i,j,n,m,A,B,k,x,mod;
long long int rasp;
int main()
{
    /*ios_base::sync_with_stdio(false);
    #ifndef ONLINE_JUDGE
        ifstream cin(".in");
        ofstream cout(".out");
    #endif*/

    f>>n>>k>>A>>B;
    for (i=1;i<=n;++i)
        {
            f>>x;
            v[i]=(v[i-1]+x)%k;
        }
    for(i=A;i<=n;++i)
        {
            ++fv[v[i]];
            if (i>B)
                {
                    --fv[v[i-(B-A+1)]];
                    mod=(mod+v[i-(B-A+1)])%k;
                }
            rasp+=fv[(v[i]+mod)%k];
        }
    g<<rasp;











    return 0;
}