#include <fstream>
#include <queue>
#define MAXN 500001
#define MAXK 100001
using namespace std;
ifstream fi("divk.in");
ofstream fo("divk.out");

queue <int> Q;
int v[MAXN],C[MAXK],n,k,A,B,i,nr,inceput,fin,sum,rez;
int main()
{
    fi>>n>>k>>A>>B;
    v[0]=0;
    for (i=1; i<=n; i++)
    {
        fi>>v[i];
        v[i]=(v[i-1]+v[i])%k;
        if (i>=A)
        {
            Q.push(v[i-A]);
            C[v[i-A]]++;
        }
        if (Q.size()>B-A+1)
        {
            C[Q.front()]--;
            Q.pop();
        }
        rez+=C[v[i]];
    }
    fo<<rez;
    fi.close();
    fo.close();
    return 0;
}
/*
#include <fstream>
#include <cstdlib>
#include <ctime>
using namespace std;
ofstream fo("divk.in");

int main()
{
    srand(time(NULL));
    fo<<"500000 7 1 500000\n";
    for (int i=1; i<=500000; i++)
        fo<<rand()%10000000;
}
*/