#include <bits/stdc++.h>
#define C__ const
#define int long long
using namespace std;
C__ int N_ = 5010, MOD = 1e9 + 7;
int n, a, b, k, dp[N_], f[N_];
signed main() {
	cin >> n >> a >> b >> k;
	for (int i = 1; i <= n; i++)
		if (i != b) dp[i] = 1;
	for (int j = n - 1; j >= 0; j--) {
		for (int i = 1; i <= n; i++)
			f[i] = (f[i - 1] + dp[i]) % MOD, dp[i] = 0;
		for (int i = 1; i <= n; i++)
			if (i != b) {
				int len = abs(i - b);
				(dp[i] += ((f[i - 1] - f[max(0LL, i - len)]) % MOD + MOD) % MOD) %= MOD;
				(dp[i] += ((f[min(n, i + len - 1)] - f[i]) % MOD + MOD) % MOD) %= MOD;
			}
	}
	cout << dp[a] % MOD << "\n";
	return 0;
}