#include <bits/stdc++.h>
using namespace std;
int n;
long long P;
int l, r;
long long fpow(long long a, long long b) {
  long long ans = 1, t = a;
  while (b) {
    if (b & 1) ans = ans * t % P;
    t = t * t % P;
    b >>= 1;
  }
  return ans;
}
void exgcd(long long a, long long b, long long& x, long long& y) {
  if (b == 0) {
    x = 1;
    y = 0;
    return;
  }
  exgcd(b, a % b, y, x);
  y -= a / b * x;
  return;
}
long long Inv(long long x) {
  long long xx, yy;
  exgcd(x, P, xx, yy);
  return (xx + P) % P;
}
long long p[21];
int N;
struct Val {
  long long x;
  int q[21];
  Val() {}
  Val(long long y) {
    memset(q, 0, sizeof(q));
    for (int i = 1; i <= N; i++)
      while (y % p[i] == 0) {
        q[i]++;
        y /= p[i];
      }
    x = y;
  }
  int calc() {
    int ans = x;
    for (int i = 1; i <= N; i++) ans = 1ll * ans * fpow(p[i], q[i]) % P;
    return ans;
  }
} fac[100010];
Val operator/(const Val& a, const Val& b) {
  Val ans;
  ans.x = a.x * Inv(b.x) % P;
  for (int i = 1; i <= N; i++) ans.q[i] = a.q[i] - b.q[i];
  return ans;
}
Val operator*(const Val& a, const Val& b) {
  Val ans;
  ans.x = a.x * b.x % P;
  for (int i = 1; i <= N; i++) ans.q[i] = a.q[i] + b.q[i];
  return ans;
}
void init() {
  long long t = P;
  for (int i = 2; i * i <= t; i++)
    if (t % i == 0) {
      p[++N] = i;
      while (t % i == 0) t /= i;
    }
  if (t > 1) p[++N] = t;
  fac[0] = Val(1);
  for (int i = 1; i <= n; i++) fac[i] = fac[i - 1] * Val(i);
  return;
}
long long C(int n, int m) {
  if (n < 0 || m < 0 || n - m < 0) return 0;
  long long res = (fac[n] / (fac[m] * fac[n - m])).calc();
  return res;
}
long long solve(int x) {
  int R = (x + r) / 2;
  R = min(R, x);
  int L = (x + l + 1) / 2;
  if (L > R) return 0;
  long long ans = (C(x, L) - C(x, R + 1) + P) % P;
  return ans;
}
int main() {
  scanf("%d %I64d %d %d", &n, &P, &l, &r);
  init();
  long long ans = 0;
  for (int i = 0; i <= n; i++) ans = (ans + C(n, i) * solve(i)) % P;
  printf("%I64d\n", ans);
}
