#include<bits/stdc++.h>
#define int long long
#pragma GCC optimize(2)
using namespace std;
int n, x, y, f[2005][2005], ans;
const int mod = 1000000007, inv2 = 500000004;
inline int calc(int p, int q) {
	if (p <= q) return 0;
	static int cnt;
	cnt = 0;
	cnt = (p - q) * (p - q - 1)  % mod;
	cnt += q * (p - q) % mod;
	cnt %= mod;
	return cnt;
}
signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> n >> x >> y;
	memset(f, 0, sizeof(f));
	if (n & 1) {
		f[0][0] = 1;
		for (int i = 1; i < n; i++) {
			if (i == x || i == y) {
				for (int j = 1; j <= i; j++) {
					f[i][j] = f[i - 1][j - 1];
				}
			} else {
				int op = (i > x) + (i > y);
				for (int j = 1; j <= i; j++) {
					f[i][j] = (f[i - 1][j - 1] + f[i - 1][j + 1] * calc(j + 1, op) % mod) % mod;
				}
			}
		}
		if (y == n) {
			ans = f[n - 1][1];
		} else if (x != n) {
			ans = f[n - 1][2];
		}
		memset(f, 0, sizeof(f));
		f[n + 1][0] = 1;
		for (int i = n; i > 1; i--) {
			if (i == x || i == y) {
				for (int j = 1; j <= (n - i + 1); j++) {
					f[i][j] = f[i + 1][j - 1];
				}
			} else {
				int op = (i < x) + (i < y);
				for (int j = 1; j <= (n - i + 1); j++) {
					f[i][j] = (f[i + 1][j - 1] + f[i + 1][j + 1] * calc(j + 1, op) % mod) % mod;
				}
			}
		}
		if (y == 1) {
			ans += f[2][1];
		} else if (x != 1) {
			ans += f[2][2];
		}
		cout << ans % mod;
	} else {
		f[0][0] = 1;
		for (int i = 1; i < n; i++) {
			if (i == x) {
				for (int j = 1; j <= i; j++) {
					f[i][j] = f[i - 1][j - 1];
				}
			} else if (i == y) {
				int op = (i > x);
				for (int j = 1; j <= i; j++) {
					f[i][j] = f[i - 1][j] * (j - op) % mod;
				}
			} else {
				int op = (i > x) + (i > y);
				for (int j = 1; j <= i; j++) {
					f[i][j] = (f[i - 1][j - 1] + f[i - 1][j + 1] * calc(j + 1, op) % mod) % mod;
				}
			}
		}
		if (y == n) {
			ans = f[n - 1][1];
		} else if (x != n) {
			ans = f[n - 1][2];
		}
		memset(f, 0, sizeof(f));
		f[n + 1][0] = 1;
		for (int i = n; i > 1; i--) {
			if (i == x ) {
				for (int j = 1; j <= (n - i + 1); j++) {
					f[i][j] = f[i + 1][j - 1];
				}
			} else if (i == y) {
				int op = (i < x);
				for (int j = 1; j <= (n - i + 1); j++) {
					f[i][j] = f[i + 1][j] * (j - op) % mod;
				}
			} else {
				int op = (i < x) + (i < y);
				for (int j = 1; j <= (n - i + 1); j++) {
					f[i][j] = (f[i + 1][j - 1] + f[i + 1][j + 1] * calc(j + 1, op) % mod) % mod;
				}
			}
		}
		if (y == 1) {
			ans += f[2][1];
		} else if (x != 1) {
			ans += f[2][2];
		}
		cout << ans % mod;
	}
}
//好多特判，纯纯狗屎

//5 3 1