#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<int>(n + 1));
dp[0][0] = 1;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
if (i == f || i == l) {
dp[i][j] = add(dp[i - 1][j], dp[i - 1][j - 1]);
} else {
int pos = j - (i > f) - (i > l);
if (pos > 0) dp[i][j] = mul(dp[i - 1][j - 1], pos);
if (j + 1 <= n) dp[i][j] = add(dp[i][j], mul(dp[i - 1][j + 1], j));
}
}
}
cout << dp[n][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();
}
}
