#include <iostream>
#include<fstream>
using namespace std;
int x,sum[500005],ap[100005],i,n,k,a,b,j1,j2;
long long tot;
int main()
{
    ifstream f("divk.in");
    ofstream g("divk.out");
    f>>n>>k>>a>>b;j1=0;j2=0;
    for(i=1;i<=n;i++)
    {
        f>>x;
        sum[i]=sum[i-1]+x;
        sum[i]%=k;
        if(i-j1>=a) {ap[sum[j1]]++;j1++;}
        if(i-j2>=b+1) {ap[sum[j2]]--;j2++;}
        tot+=(1LL)*ap[sum[i]];
    }
    g<<tot;
    return 0;
}