#include <bits/stdc++.h>

using namespace std;

ifstream f("divk.in");
ofstream g("divk.out");

int x[500002],s[500002];

int main()
{
    int n,k,a,b,i,j,nr=0,m=0;
    f>>n>>k>>a>>b;
    for(i=1;i<=n;i++)
    {
        f>>x[i];
        s[i]=s[i+1]+x[i];
        if(i>=min(a,b));
        for(j=min(a,b);j<=min(max(a,b),i);j++)
        {
            m=s[i]-s[i-j];
            if(m%k==0)
                nr++;
        }
    }
    g<<nr;

    return 0;
}