#include<stdio.h>
int n,k,a,b,i,c,v[100001];
long long s[500001],t;
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;
        if(i>b&&v[s[i-b-1]%k]>0)
            v[s[i-b-1]%k]--;
        if(i>=a)
            v[s[i-a]%k]++;
        t+=v[s[i]%k];
    }
    printf("%lld",t);
}