#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("avx2,fma")
#define rep(i,l,r) for (int i = l; i < r; i++)
#define repr(i,r,l) for (int i = r; i >= l; i--)
#define X first
#define Y second
#define pb push_back
#define endl '\n'
#define debug(x) cerr << #x << " : " << x << endl;
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pll;
const long long int N = 2e3+20,mod = 1e9+7,inf = 1e18+10,sq = 32000;
inline int mkay(int a,int b){
if (a+b >= mod) return a+b-mod;
if (a+b < 0) return a+b+mod;
return a+b;
}
inline int poww(int n,int k){
int c = 1;
while (k){
if (k&1) c = (1ll*c*n)%mod;
n = (1ll*n*n)%mod;
k >>= 1;
}
return c;
}
int dp[2][N][N][2],pre[2][N][N][2];
int main(){
ios :: sync_with_stdio(0); cin.tie(0);
int n,s,f;
cin >> n >> s >> f;
if (s > f) swap(s,f);
if ((n&1) && n > 1000 && f-s < 1000){
f = f-s+1;
s = 1;
}
swap(f,s);
dp[1][1][1][0] = 1;
dp[1][1][1][1] = 1;
pre[1][1][1][1] = 1;
pre[1][1][1][0] = 1;
rep(i,2,n+1){
int d = (i&1);
int r = min(i,f);
rep(j,1,r+1){
rep(k,1,i+1){
if (j == k){
dp[d][j][k][0] = 0;
dp[d][j][k][1] = 0;
pre[d][j][k][0] = pre[d][j][k-1][0];
pre[d][j][k][1] = pre[d][j][k-1][1];
continue;
}
if (j > k){
dp[d][j][k][0] = pre[1-d][j-1][k-1][1];
dp[d][j][k][1] = mkay(pre[1-d][j-1][i-1][0],-pre[1-d][j-1][k-1][0]);
}
else{
dp[d][j][k][0] = pre[1-d][j][k-1][1];
dp[d][j][k][1] = mkay(pre[1-d][j][i-1][0],-pre[1-d][j][k-1][0]);
}
pre[d][j][k][0] = mkay(pre[d][j][k-1][0],dp[d][j][k][0]);
pre[d][j][k][1] = mkay(pre[d][j][k-1][1],dp[d][j][k][1]);
}
}
}
int d = (n&1);
cout << mkay(dp[d][f][s][0],dp[d][f][s][1]);
}
