#include<cstdio>
int v[500001],sum,vc[100001],a,b,n,m,i,j,k,s,cate,p1,s1[500001];
int main ()
{
freopen("divk.in","r",stdin);
freopen("divk.out","w",stdout);
scanf("%d%d%d%d",&n,&k,&a,&b);
vc[0]=1;
for(i=1;i<=n;i++)
    {
    scanf("%d",&v[i]);
    s+=v[i];
    s%=k;
    s1[i]=s;
    if(i>=a)
        {
        for(j=i-a+1;j>=i-b&&j>=1;j--)
            if(s1[i]==s1[j])
                sum++;
        }
    }
printf("%d",sum);
return 0;
}