/*input
4 2 3
*/
#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const ll modulo = 1000000007;
int sgn(ll x)
{
if (x < 0)
return -1;
if (x > 0)
return 1;
return 0;
}
map<tuple<int, int, int, int>, ll>M;
ll f(int n, int a, int b, int s)
{
if (a == b)
return 0;
if (M.count(make_tuple(n, a, b, s)))
return M[make_tuple(n, a, b, s)];
if (n == 2)
{
if (sgn(b - a) != s)
return 0;
else
return 1;
}
ll ret = 0;
for (int c = 1; c <= n; c++)
{
if (sgn(b - c) == s)
{
ret += f(n - 1, a - (a > b), c - (c > b), -s);
}
}
ret %= modulo;
return M[make_tuple(n, a, b, s)] = ret;
}
int main()
{
int n, a, b;
cin >> n >> a >> b;
ll ans = f(n, a, b, 1) + f(n, a, b, -1);
ans %= modulo;
cout << ans << "\n";
}
