#include <bits/stdc++.h>
#include <queue>
#include <vector>

using namespace std;

struct Node {
    int val;
    int depth;
    
    Node(int v, int d) {
        val = v;
        depth = d;
    }
    
    std::vector<Node> children;
};

long countArray(int n, int k, int x) {
    // Return the number of ways to fill in the array.
      
    //bfs
    std::queue<Node> nodes;
    int depth = 0;
    int count = 0;
    
    for (int i = 1; i < n; i++) {
        if (i != x) {
            nodes.push(Node(i, 1));
        }
    }
    
    while (!nodes.empty()) {
        Node cur = nodes.front();
        nodes.pop();
          
        if (cur.depth == n-2) 
        {
            if (cur.val != 1) 
            {
                count = (count+1) % 1000000007;
                continue;
            }
        }
        else 
        {
            for (int i = 1; i < n; i++) {
                if (i != cur.val) {
                    nodes.push(Node(i, cur.depth+1));
                }
            }
        }
    }
    
    return count;
}

int main() {
    int n;
    int k;
    int x;
    cin >> n >> k >> x;
    long answer = countArray(n, k, x);
    cout << answer << endl;
    return 0;
}