#include <fstream>

using namespace std;
ifstream in ("divk.in");
ofstream out("divk.out");
long long f[1000009], v[1000000], k, a, b, i, n, sol;

int main()
{
    in >> n >> k >> a >> b;
    for ( i=1;  i <= n; i++ ){
        in>>v[i];
        v[i] += v[i-1];
        v[i] %= k;
    }
    for ( i=a; i <= n; i++ ){
        f[ v[i-a+1] ] ++;
        if ( i>b ) f[ v[i-b] ]--;
        sol += f[v[i]];
    }
    out<<sol;
    return 0;
}