#include <bits/stdc++.h>
using namespace std;
using i64 = int_fast64_t;
using ui64 = uint_fast64_t;
#define REP(i, n) for (i64 (i) = 0; (i) < (n); ++(i))
#define FOR(i, a, b) for (i64 (i) = (a); (i) < (b); ++(i))

constexpr int MOD = (int)1e9 + 7;
ui64 MOP(ui64 x, ui64 n, ui64 m = MOD) {
    ui64 r = 1;
    while (n > 0) {
        if (n & 1) (r *= x) %= m;
        (x *= x) %= m;
        n >>= 1;
    }
    return r;
}

int D, L, R, K;
vector<ui64> fact, dep;

signed main() {

    cin >> D >> L >> R >> K;

    if (K > D * 2) {
        cout << -1 << endl;
        return 0;
    }
    
    dep.resize(D + 1);
    dep[0] = dep[1] = 1;
    REP(i, D - 1) dep[i + 2] = dep[i + 1] * 2;

    fact.resize(2100100);
    fact[0] = fact[1] = 1;
    REP(i, 2100108) fact[i + 2] = (fact[i + 1] * (i + 2)) % MOD;
    
    ui64 dl = 0, dr = 0;
    {
        int tmp = L;
        while (tmp > 0) {
            ++dl;
            tmp >>= 1;
        }
        tmp = R;
        while (tmp > 0) {
            ++dr;
            tmp >>= 1;
        }
    }

    ui64 res = 0;
    if (dl == dr) {
        if (K % 2 == 1) {
            cout << 0 << endl;
            return 0;
        }
        K >>= 1;
        res = dep[K];
        REP(i, K) (res <<= 1) %= MOD;
        res *= dep[dl - K];
        for (int i = 1; i <= D; ++i) {
            if (i == dl) {
                res *= fact[dep[i] - 2];
            } else {
                res *= fact[dep[i]];
            }
            res %= MOD;
        }
    } else {
        int dif = dr - dl;
        if (K - dif % 2 == 1) {
            cout << 0 << endl;
            return 0;
        }
        int k = (K - dif) >> 1;
        res = dep[k] * dep[dr];
        for (int i = 1; i <= D; ++i) {
            if (i == dl or i == dr) {
                res *= fact[dep[i] - 1];
            } else {
                res *= fact[dep[i]];
            }
            res %= MOD;
        }
    }

    cout << res << endl;

}