#include<iostream>
#include<vector>
using namespace std;
#define ll long long
#define ld long double
#define pii pair<ll, ll>
#define RUN_LIKE_DJAWAD (ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0));
#define pb push_back
#define pf push_front
#define ff first
#define ss second
#define maxn 2001
const int mod = 1e9 + 7;
int dp[maxn][2][maxn];
int n, s, e;
int pd[maxn][2][maxn];
int smp[maxn][2];
int main(){
RUN_LIKE_DJAWAD
dp[1][0][1] = 1, dp[1][1][1];
for (int i = 2; i < maxn; i++){
int sm = 0;
for (int j = i - 1; j > 0; j--){
sm = (sm + dp[i - 1][1][j]) % mod;
dp[i][0][j] = sm;
}
sm = 0;
for (int j = 2; j <= i; j++){
sm = (sm + dp[i - 1][0][j - 1]) % mod;
dp[i][1][j] = sm;
}
}
cin >> n >> s >> e;
if (e < s) swap(s, e);
int cc = e - 1;
int d = n - e;
for (int ne = n; ne >= e; ne--){
for (int c = 0; c <= ne - e; c++){
bool bt = (n - c - 2) & 1;
if (bt){
int a0 = smp[c + 1][1], a1 = (dp[n - c - 1][0][s] + dp[n - c - 1][1][s] - smp[c + 1][0] + mod) % mod;
smp[c][0] = (smp[c][0] + a0) % mod;
smp[c][1] = (smp[c][1] + a1) % mod;
pd[ne][0][c] = a0;
pd[ne][1][c] = a1;
} else {
int a1 = smp[c + 1][1], a0 = (dp[n - c - 1][0][s] + dp[n - c - 1][1][s] - smp[c + 1][0] + mod) % mod;
smp[c][0] = (smp[c][0] + a0) % mod;
smp[c][1] = (smp[c][1] + a1) % mod;
pd[ne][0][c] = a0;
pd[ne][1][c] = a1;
}
}
}
cout << (pd[e][0][0] + pd[e][1][0]) % mod << "\n";
}
