//#include <iostream>
#include <fstream>
using namespace std;
int n,k,a,b,f[500005],sp[500005],sum;
ifstream cin("divk.in");
ofstream cout("divk.out");
int main()
{
    cin>>n>>k>>a>>b;
    for(int i=1;i<=n;i++){
        cin>>sp[i];
        sp[i]+=sp[i-1];
        sp[i]%=k;
    }
    for(int i=1;i<=n;i++){
        if(i>=a){
            f[sp[i-a]]++;
        }
        if(i>b){
            f[sp[i-b-1]]--;
        }
        sum+=f[sp[i]];
    }
    cout<<sum;
    return 0;
}