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