#include <fstream>
#include <iostream>
#define maxn 500001
#define INF 0x3f3f3f3f
using namespace std;

int n, k, a, b, sol;
long long sum[maxn];

ifstream f("divk.in");
ofstream g("divk.out");

int main(){

    f >> n >> k >> a >> b;

    for(int i = 1; i <= n; ++i){
        f >> sum[i];
        sum[i] += sum[i-1];
    }

    for(int i = 1; i <= n; ++i){
        if(i >= a){
            for(int j = i - b; j <= i - a; ++j){
                if((sum[i] - sum[j]) % k == 0) ++sol;
            }
        }
    }

    g << sol << '\n';

}