#include <bits/stdc++.h>
using namespace std;
const int MOD = (int) 1e9 + 7;
/** Assumes 1 <= a, b < MOD */
int add(int a, int b) {
if (a + b >= MOD) return a + b - MOD;
return a + b;
}
/** Assumes 1 <= a, b < MOD */
int sub(int a, int b) {
return add(a, MOD - b);
}
/** Assumes 1 <= a, b < MOD */
int mul(int a, int b) {
return (long long) a * b % MOD;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, cs, cf;
cin >> n >> cs >> cf;
vector< vector<int> > dp(n + 1, vector<int>(n + 1, 0));
dp[0][0] = 1;
for (int i = 1; i <= n; i++) {
for (int j = 1; j < n; j++) {
if (i == cs || i == cf) {
dp[i][j] = add(dp[i - 1][j], dp[i - 1][j - 1]);
} else {
dp[i][j] = add(mul(dp[i - 1][j - 1], j - (i > cs) - (i > cf)), mul(dp[i - 1][j + 1], j));
}
}
}
cout << dp[n][1] << '\n';
return 0;
}
