#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("divk.in");
ofstream fout("divk.out");
int n,k,nr1,nr2,nr;
int a[500005];
long long s[500005];
int main()
{
    int i,j,x;
fin>>n>>k>>nr1>>nr2;
for(i=1;i<=n;i++)
    {fin>>x;
    a[i]=a[i-1]+x;
    if(i-nr1>=0)
        {s[a[i-nr1]%k]++;
        nr+=s[a[i]%k];
        }
    if(i-nr2-1>=0)
        s[a[i-nr2-1]%k]--;
    }
fout<<nr;
    return 0;
}