#include <bits/stdc++.h>
using namespace std;
ifstream in("divk.in");
ofstream out("divk.out");
int a[500005],s[100005],n,x,y,m;
int main()
{
    in>>n>>m>>x>>y;
    long long sol=0;
    for(int i=1;i<=n;i++)
    {
        in>>a[i];
        a[i]=(a[i-1]+a[i])%m;
        if(i>=x)s[a[i-x]]++;
        if(i>y)s[a[i-y-1]]--;
        sol+=s[a[i]];
    }
    out<<sol;
    return 0;
}