#include<stdio.h>
int n,k,a,b,i,c,v[100001],t;
long long s[500001];
int main() {
    freopen("divk.in","r",stdin),freopen("divk.out","w",stdout),scanf("%d%d%d%d",&n,&k,&a,&b);
    for(v[0]=i=1;i<=n;i++)
        scanf("%d",&c),s[i]=s[i-1]+c;
    for(i=a;i<b;i++)
        v[s[i-a+1]%k]++,t+=v[s[i]%k];
    for(i=b;i<=n;i++)
        v[s[i-a+1]%k]++,t+=v[s[i]%k],v[s[i-b]%k]--;
    printf("%d",t);
}