#include<stdio.h>
int i,n,k,a,b,c,r[100005],s[500005];
long long l;
int main() {
    freopen("divk.in","r",stdin),freopen("divk.out","w",stdout),scanf("%d%d%d%d",&n,&k,&a,&b);
    for(r[0]=i=1;i<=n;i++)
        scanf("%d",&c),s[i]=(s[i-1]+c)%k;
    for(i=a;i<=n;i++) {
        l+=r[s[i]];
        r[s[i-a+1]]++;
        if(i>=b)
            r[s[i-b]]--;
    }
    printf("%lld",l);
}