#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("divk.in");
ofstream fout("divk.out");
const int NMax=500005;
const int Kmax=100005;
int N,K,A,B,S[NMax],P[Kmax];
long long sol;
void Read()
{
     int x;
    fin>>N>>K>>A>>B;
    for(int i=1;i<=N;++i)
    {
        fin>>x;
        S[i]=(S[i-1]+x)%K;
    }

}

void Solve()
{
    for(int i=A;i<=N;++i)
    {
        P[S[i-A]]++;
        if(i>B)
        {
            P[S[i-B-1]]--;
        }
        sol=sol+P[S[i]];
    }
    fout<<sol<<"\n";
}
int main()
{
    Read();
    Solve();

    return 0;
}