#include <bits/stdc++.h>
#define FOR(x, a, b) for (int x = a; x <= b; ++x)
#define FOD(x, a, b) for (int x = a; x >= b; --x)
#define REP(x, a, b) for (int x = a; x < b; ++x)
#define DEBUG(X) { cout << #X << " = " << X << endl; }
#define PR(A, n) { cout << #A << " = "; FOR(_, 1, n) cout << A[_] << " "; cout << endl; }
#define PR0(A, n) { cout << #A << " = "; REP(_, 0, n) cout << A[_] << " "; cout << endl; }
using namespace std;
typedef long long LL;
const int N = 2e3 + 10;
const int BASE = 1e9 + 7;
int n, s, t;
int dp[N][N][2][2];
void Update(int &a, int b) {
a += b; if (a >= BASE) a -= BASE;
}
LL P2(LL n) {
return n * (n - 1) % BASE;
}
int Compute(int i, int j, int L, int R) {
if (j < 0) return 0;
if (i == n) return (j == 0) ? 1 : 0;
int &ans = dp[i][j][L][R];
if (ans != -1) return ans;
ans = 0;
if (i == s) {
Update(ans, Compute(i + 1, j, 1, R));
Update(ans, (LL)j * Compute(i + 1, j - 1, 1, R) % BASE);
} else if (i == t) {
Update(ans, Compute(i + 1, j, L, 1));
Update(ans, (LL)j * Compute(i + 1, j - 1, L, 1) % BASE);
} else {
Update(ans, Compute(i + 1, j + 1, L, R));
if (L == 1) Update(ans, (LL)j * Compute(i + 1, j - 1, L, R) % BASE);
if (R == 1) Update(ans, (LL)j * Compute(i + 1, j - 1, L, R) % BASE);
Update(ans, P2(j) * Compute(i + 1, j - 1, L, R) % BASE);
}
return ans;
}
int main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif // LOCAL
scanf("%d%d%d", &n, &s, &t);
memset(dp, -1, sizeof dp);
printf("%d", Compute(1, 0, 0, 0));
return 0;
}
