#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("divk.in");
ofstream fout("divk.out");
int n, k, a, b, result;
int x;
int main()
{
    fin >> n >> k >> a >> b;
    vector<int>s(n+1);
    vector<int>freq(k);
    for(int i = 1; i <= n; i++)
    {
        fin >> x;
        s[i] = (x % k + s[i-1])%k;

    }

    freq[0] = 1;
    for(int i = a; i <= n; i++)
    {
        result += freq[s[i]];
        if( i - b> 0)
            freq[s[i-b-1]]--;
        freq[s[i-a+1]]++;
    }
    fout << result;
    return 0;
}