#include<stdio.h>
#include<algorithm>
#define maxn 500005
#define maxk 100005
#define maxb 8192
using namespace std;

#define nxt if(++pos==maxb) fread(buff,1,maxb,stdin),pos=0
int n,K,A,B;
int a[maxn],nr[maxk];
long long s[maxn];
long long sol;
char buff[maxb];
int pos=0;

int get()
{
    int nr=0;
    while(buff[pos]<'0' || buff[pos]>'9') nxt;
    while(buff[pos]>='0' && buff[pos]<='9'){
        nr=nr*10+buff[pos]-'0';
        nxt;
    }
    return nr;
}

void read()
{
    n=get(); K=get(); A=get(); B=get();
    for(int i=1;i<=n;i++)
     a[i]=get();
}

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;
}