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