#include <bits/stdc++.h>
#define all(x) begin(x), end(x)
using namespace std;
using ll = long long;
const char nl = '\n', sp = ' ';
const int mod = 1e9 + 7;
inline int add(int a, int b) {
return (__int128(a) + b) % mod;
}
inline int mul(int a, int b) {
return (__int128(a) * b) % mod;
}
void solve() {
int n, f, l;
cin >> n >> f >> l;
vector dp(n + 1, vector(n + 1, vector(2, vector<int>(2))));
dp[0][0][0][0] = 1;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
for (int ff = 0; ff < 2; ff++) {
for (int lf = 0; lf < 2; lf++) {
if (i == f) {
if (!ff) continue;
dp[i][j][1][lf] = add(dp[i - 1][j][0][lf], dp[i - 1][j - 1][0][lf]);
} else if (i == l) {
if (!lf) continue;
dp[i][j][ff][1] = add(dp[i - 1][j][ff][0], dp[i - 1][j - 1][ff][0]);
} else {
if (j - ff - lf > 0) dp[i][j][ff][lf] = mul(dp[i - 1][j - 1][ff][lf], j - ff - lf);
if (j + 1 <= n) dp[i][j][ff][lf] = add(dp[i][j][ff][lf], dp[i - 1][j + 1][ff][lf]);
}
}
}
}
}
cout << dp[n][1][1][1] << nl;
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
#ifdef LOCAL
freopen("../in.txt", "r", stdin);
freopen("../out.txt", "w", stdout);
#endif
int t = 1;
// cin >> t;
while (t--) {
solve();
}
}
