#include<fstream>
using namespace std;
ifstream r("divk.in");
ofstream w("divk.out");
int v[500001],f[99999],n,a,b,k,i,x;
long long c;
int main()
{
    for(r>>n>>k>>a>>b,i=1;i<=n;++i) {
        r>>x,v[i]=(v[i-1]+x)%k;
        if(i>=a)
            ++f[v[i-a]];
        if(i>b)
            --f[v[i-b-1]];
        c+=f[v[i]];
    }
    w<<c;
    return 0;
}