#include<fstream.h>
ifstream f("divk.in");
ofstream g("divk.out");
long long v[500000],nr,n,a,b,k,x,i,j,p;
int main(){
f>>n>>k>>a>>b;v[0]=0;
for(i=1;i<=n&&i<a;i++)
   {f>>x;
   v[i]=v[i-1]+x;}

for(i;i<=n;i++)
   {f>>x;
   v[i]=v[i-1]+x;
      if(i-b<=0)
	      p=1;
        else p=i-b;
    for(j=p;j<=i-a+1;j++)
       if((v[i]-v[j-1])%k==0)   
		 nr++;}



g<<nr;
return 0;   
}