#include<stdio.h>
#include<algorithm>
#define maxn 500005
#define maxk 100005
using namespace std;

int n,K,A,B;
int a[maxn],nr[maxk];
long long s[maxn];
long long sol;

void read()
{
    scanf("%d %d %d %d",&n,&K,&A,&B);
    for(int i=1;i<=n;i++)
     scanf("%d ",&a[i]);
}

void solve()
{
    for(int i=1;i<=n;i++) s[i]=s[i-1]+a[i];

    nr[0]=1;
    for(int i=A;i<=n;i++)
    {
        sol+=nr[s[i]%K];
        nr[s[i-A+1]%K]++;

        if(i>=B) nr[s[i-B]%K]--;
    }
}

int main()
{
    freopen("divk.in","r",stdin);
    freopen("divk.out","w",stdout);

    read();
    solve();
    printf("%lld",sol);

    fclose(stdin);
    fclose(stdout);
    return 0;
}