#include <fstream>
#include <vector>
using namespace std;

ifstream cin("divk.in");
ofstream cout("divk.out");

#define int long long

int sp[100005],vf[100005];

int32_t main()
{
    int n,k,a,b,x,cf=0;
    cin>>n>>k>>a>>b;
    for (int i=1; i<=n; i++)
    {
        cin>>x;
        sp[i]=sp[i-1]+x;
        sp[i]%=k;
    }
    for (int i=a; i<=n; i++)
    {
        vf[sp[i-a+1]]++;
        if (i-b>0) vf[sp[i-b]]--;
        cf+=vf[sp[i]];
    }
    cout<<cf;
}
/*
* * * * * * * * *
1 2 3 4 5 6 7 8 9
*/