/* -*- coding: utf-8 -*-
 *
 * 916.cc:  No.916 Encounter On A Tree - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_D = 20;
const int MAX_N = 1 << MAX_D;
const int MOD = 1000000007;

/* typedef */

typedef long long ll;

/* global variables */

int rgs[MAX_D + 1], ds[MAX_N], fracs[MAX_N];

/* subroutines */

/* main */

int main() {
  int d, l, r, k;
  scanf("%d%d%d%d", &d, &l, &r, &k);
  l--, r--;

  rgs[0] = 0;
  for (int i = 0; i < d; i++)
    rgs[i + 1] = rgs[i] + (1 << i);
  //for (int i = 0; i <= d; i++) printf("%d ", rgs[i]); putchar('\n');

  int n = (1 << d) - 1;
  fracs[0] = 1;
  for (int i = 0, j = 0; i < n; i++) {
    if (i == rgs[j]) j++;
    ds[i] = j - 1;
    fracs[i + 1] = (ll)fracs[i] * (i + 1) % MOD;
  }
  //for (int i = 0; i < n; i++) printf("%d ", ds[i]); putchar('\n');

  int dd = ds[r] - ds[l];

  if (k < dd || ((k - dd) & 1) != 0) {
    puts("0");
    return 0;
  }

  int dc = ds[l] - (k - dd) / 2;
  if (dc < 0) {
    puts("0");
    return 0;
  }
  //printf("dl=%d, dr=%d, dc=%d\n", ds[l], ds[r], dc);

  int hl = ds[l] - dc, hr = ds[r] - dc;
  int cnt = 1;
  if (hl == hr) {
    int mi = 1 << ds[r], mh = 1 << (hr - 1);
    for (int i = 0; i < d; i++) {
      if (i == ds[r])
	cnt = (ll)cnt * mi % MOD * mh % MOD * fracs[mi - 2] % MOD;
      else cnt = (ll)cnt * fracs[1 << i] % MOD;
    }
  }
  else {
    int mr = 1 << ((hl == 0) ? hr : hr - 1);
    for (int i = 0; i < d; i++) {
      if (i == ds[r]) cnt = (ll)cnt * mr % MOD * fracs[(1 << i) - 1] % MOD;
      else cnt = (ll)cnt * fracs[1 << i] % MOD;
    }
  }

  printf("%d\n", cnt);
  return 0;
}