#include<bits/stdc++.h>
using namespace std;
int n,k;
int v[500005],a,b,x,sum[500005],s,sol,d,frecv[100005],a1,b1,rest;
int main()
{
    freopen("divk.in","r",stdin);
    freopen("divk.out","w",stdout);
    scanf("%d%d%d%d",&n,&k,&a,&b);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&x);
        v[i]=x%k;
    }
    for(int i=1;i<=n;i++)
    {
        sum[i]=(sum[i-1]+v[i])%k;
    }
    for(int i=a;i<=b;i++)
    {
        if(!sum[i]) sol++;
    }
    d=b-a+1;
    for(int i=1;i<=d;i++)
    {
        frecv[sum[i]]++;
    }
    a1=1;
    b1=d;
    for(int i=(b+1);i<=n;i++)
    {
        x=sum[i];
        rest=k-x;
        if(rest==k) rest=0;

            sol=sol+frecv[x];
        b1++;
        frecv[sum[b1]]++;
        frecv[sum[a1]]--;
        a1++;
    }
    printf("%d\n",sol);
}