#include <bits/stdc++.h>

using namespace std;

using ll = int64_t;

const int MAXN = 5e5, MAXK = 1e5;

int car[1 + MAXK];
int s[1 + MAXN];
int n, k;
ll solve (int l) {
  register int i;
  register ll sol = 0;
  if (l == 0)
    return 0;
  car[0]++;
  for (i = 1; i <= n; i++) {
    if (i > l)
      car[s[i - l - 1]]--;
    sol = sol + car[s[i] ];
    car[s[i]]++;
  }
  for (i = n - l; i <= n; i++)
    car[s[i]]--;
  return sol;
}

const int SIZE = 1 << 10;

char buffer[SIZE];

int pointer = 0;

static inline char advance () {
  if (pointer == SIZE) {
    pointer = 0;
    fread (buffer, SIZE, 1, stdin);
  }
  return buffer[pointer++];
}

static inline int read () {
  register int answear = 0;
  register char ch = advance ();
  while (!isdigit (ch))
    ch = advance ();
  while (isdigit (ch)) {
    answear = answear * 10 + ch - '0';
    ch = advance ();
  }
  return answear;
}

int main() {
  register int a, b, i;
  freopen ("divk.in", "r", stdin);
  freopen ("divk.out", "w", stdout);
  n = read ();
  k = read (); a = read (); b = read ();
  for (i = 1; i <= n; i++) {
    s[i] = s[i - 1] + read ();
    if (s[i] >= k)
      s[i] -= k;
  }
  printf ("%lld\n", solve (b) - solve (a - 1));
  return 0;
}