#include<fstream.h>
//using namespace std;
ifstream f1 ("divk.in");
ofstream f2 ("divk.out");
int v[500001],r[100000];
long long s[500001];
int main()
{
int n,k,a,b,i,j,nr;
f1>>n>>k>>a>>b;
for (i=1; i<=n; i++) {f1>>v[i]; s[i]=s[i-1]+v[i];}
for (i=1;i<=b-a+2; i++) r[s[i]%k]++;
for (i=b+1; i<=n; i++)
{
 nr+=r[s[i]%k];
 r[s[i-b+1]%k]--;
 r[s[i-a+2]%k]++;
}
f2<<nr;
return 0;
}