//make sure to make new file!
import java.io.*;
import java.util.*;
//connected components dp practice
public class kangaroo{
public static long MOD = 1000000007L;
public static void main(String[] args)throws IOException{
BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
PrintWriter out = new PrintWriter(System.out);
StringTokenizer st = new StringTokenizer(f.readLine());
int n = Integer.parseInt(st.nextToken());
int cs = Integer.parseInt(st.nextToken())-1;
int cf = Integer.parseInt(st.nextToken())-1;
//dp[x][y] -> # of ways to make the # of jump of first x indeces, such that there are y components formed
//ex: jumps 2 -> 5 -> 1 -> 4 -> 3, make components starting from the 1
//no component can ever be like 123 or 321, where 2nd < 1st or 2nd to last > last
//going back and forth means you can't have a_(x-1) < a_x < a_(x+1) and vice versa
//if not start/end, can never have a_(x-1) < a_x, because the next element is guaranteed t
long[][] dp = new long[n][n+1];
dp[0][1] = 1L;
for(int k = 0; k < n-1; k++){
for(int j = 1; j <= n; j++){
if(dp[k][j] == 0L) continue;
if(k+1 == cs || k+1 == cf){
//make new component at beginning/end
dp[k+1][j+1] = (dp[k+1][j+1] + dp[k][j] + MOD)%MOD;
//add to first/last component
dp[k+1][j] = (dp[k+1][j] + dp[k][j] + MOD)%MOD;
} else {
//make new component
dp[k+1][j+1] = (dp[k+1][j+1] + dp[k][j] * (long)(j+1) + MOD)%MOD;
//join components
if(j > 1){
dp[k+1][j-1] = (dp[k+1][j-1] + dp[k][j] * (long)(j-1) + MOD)%MOD;
}
}
}
}
/*
for(int k = 0; k < n; k++){
for(int j = 1; j <= n; j++){
out.print(dp[k][j] + " ");
}
out.println();
}*/
out.println(dp[n-1][1]);
out.close();
}
}
