#include <fstream>
using namespace std;
ifstream fin("divk.in");
ofstream fout("divk.out");
int n,i,k,a,b,f[100001],v[500001];
long long sol;
int main(){
    fin>>n>>k>>a>>b;
    for(i=1;i<=n;i++){
        fin>>v[i];
        v[i]+=v[i-1];
        v[i]%=k;
    }
    for(i=a;i<=n;i++){
        f[v[i-a]]++;
        if(i>b)f[v[i-b-1]]--;
        sol+=f[v[i]];
    }
    fout<<sol;
    return 0;
}