#include <fstream>
using namespace std;
ifstream f("divk.in");
ofstream g("divk.out");
int N, K, A, B, nr, V[500010],i,j;

int main()
{
    f>>N>>K>>A>>B;
    for (i = 1; i <= N; i++)
     {
        f>>V[i];
        V[i]=(V[i] + V[i - 1])%pK;
    }

    for (i=A;i<=B;i++)
    {
        for (j=i;j<=N;j++)
        {
            if (V[j]==V[j-i])
            nr++;
        }
    }
   g<<nr<< '\n';
    return 0;
}