#include <bits/stdc++.h>
//#define int long long
FILE *in= fopen("divk.in","r");
FILE *out= fopen("divk.in","w");
using namespace std;
int v[500005];
int sp[500005];
int f[200005];
int32_t main()
{
    int n,k,a,b;
    fscanf(in,"%d %d %d %d",&n,&k,&a,&b);
    for(int i=1;i<=n;++i)
    {
        fscanf(in,"%d",&v[i]);
        sp[i]=(sp[i-1]+v[i])%k;
    }
    long long ans=0;
    for(int i=a;i<=b;++i)
    {
        f[sp[i-a]]++;
        if(i>=a)ans +=1LL*(f[sp[i]]);
    }
    int lost=1;
    for(int i=b+1;i<=n;++i)
    {
        f[sp[i-a]]++;
        f[sp[i-b-1]]--;
        ans+=1LL*(f[sp[i]]);
    }
    fprintf(out,"%lld",ans);
    return 0;
}