#include <iostream>
#include <fstream>
#define nmax 500005
using namespace std;
ifstream fin("divk.in");
ofstream fout("divk.out");
long r[nmax];
int main()
{long n,k,a,b,i,j,x,fina,nr=0;

    fin>>n>>k>>a>>b;
    r[0]=0;

    for(i=1;i<=n;i++)
    {
        fin>>x;
        r[i]=(x+r[i-1])%k;
    }

    for(i=1;i<=n-a+1;i++)
    {fina=min(i+b-1,n);
        for(j=i+a-1;j<=fina;j++)
        {if(r[j]==r[i])nr++;
        }
     }

fout<<nr;
}