#pragma GCC optimize("O3")
#include <fstream>
#include <vector>
#define NMAX 500000

using namespace std;

int n, k, a, b;
long long sum, sol;
vector <int> v[NMAX+10];

void solve(int r)
{   int p1 = 0, p2 = 0, val;
    for(int i=1; i<v[r].size(); i++)
        {   val = v[r][i] - b;
            while(v[r][p1] < val) p1++;
            val = v[r][i] - a + 1;
            while(v[r][p2] < val) p2++;
            sol = sol + (long long)p2 - (long long)p1;
        }
}

int main()
{
    ifstream cin("divk.in");
    ofstream cout("divk.out");
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin >> n >> k >> a >> b;
    v[0].push_back(0);
    for(int i=1; i<=n; i++)
        {   long long x;
            cin >> x;
            sum += x;
            v[sum%k].push_back(i);
        }
    for(int i=0; i<n; i++) solve(i);
    cout << sol << '\n';
    return 0;
}