#include <stdio.h>
int n,a,b,k;
int sum[500001];
int main()
{
    FILE *fin,*fout;
    fin=fopen("divk.in","r");
    fout=fopen("divk.out","w");
    fscanf(fin,"%d%d%d%d",&n,&k,&a,&b);
    for(int i=1;i<=n;i++)
    {
        fscanf(fin,"%d",&sum[i]);
        sum[i]+=sum[i-1];
        if(sum[i]>=k) sum[i]%=k;
    }
    int ct=0;
    for(int i=a;i<=n;i++)
    {
            for(int j=a;;j++)
            {
                    if(j>b||i-j==-1) break;
                    if(sum[i]==sum[i-j]) ct++;
            }
    }
    fprintf(fout,"%d\n",ct);
    fclose(fin);
    fclose(fout);
    return 0;
}