#include<cstdio>
#include<cstring>
#include<queue>
#include<vector>
using namespace std;
int n,K,A,B,i,s[500009],a[500009],ap[500009];
long long nr;
int main()
{
freopen("divk.in","r",stdin);
freopen("divk.out","w",stdout);
scanf("%d",&n);
scanf("%d",&K);
scanf("%d",&A);
scanf("%d",&B);
for(i=1;i<=n;i++)
{
    scanf("%d",&a[i]);
    a[i]%=K;
}
for(i=1;i<=n;i++)
{
    s[i]=s[i-1]+a[i];
    if(s[i]>=K) s[i]-=K;
}
ap[0]=1;
for(i=A;i<=n;i++)
{
    nr+=ap[s[i]];
    if(i>=B) ap[s[i-B]]--;
    ap[s[i-A+1]]++;
}
printf("%lld\n",nr);
return 0;
}