#include <bits/stdc++.h>
#define maxN 500002
#define maxK 100002
#define ll long long
using namespace std;
int n, a, b, k, v[maxN], s[maxK], aps[maxK];
ll sol;
void read()
{
    int i;
    freopen("divk.in", "r", stdin);
    scanf("%d %d %d %d", &n, &k, &a, &b);
    for (i = 1; i <= n; ++ i)
    {
        int x;
        scanf("%d", &x);
        s[i] = (s[i - 1] + x) % k;
    }
}
void solve()
{
    int i, j;
    aps[0] = 1;
    for (i = a; i <= n; ++ i)
    {
        if (i > b)
           -- aps[s[i - b]];
        sol += 1LL * aps[s[i]];
                ++ aps[s[i - a]];
        if (i == b)
            -- aps[0];
    }
}
void write()
{
    freopen("divk.out", "w", stdout);
    printf("%lld", sol);
}
int main()
{
    read();
    solve();
    write();
    return 0;
}