#include<bits/stdc++.h>
#pragma GCC optimize(2)
#define mod 1000000007LL
using namespace std;

int N, A, B, K;
long long ans = 0;
long long dp[5005][5005];
int cnt[5005];

int main(){
#ifndef ONLINE_JUDGE
    freopen("../data.in", "r", stdin);
    freopen("../data.out", "w", stdout);
#endif

	scanf("%d %d %d %d", &N, &A, &B, &K);
	dp[0][A] = 1;
	for (int i = 1; i <= N; i ++){
		if (i == B) continue;
		for (int j = 1; j <= N; j ++){
			if (i == j) continue;
			if (j == B) continue;
			if (abs(i - j) >= abs(i - B)) continue;
			cnt[i] ++;
		}
	}
	for (int i = 0; i < N; i ++){
		for (int j = 1; j <= N; j ++){
			if (j == B) continue;
			for (int k = 1; k <= N; k ++){
				if (j == k) continue;
				if (k == B) continue;
				if (abs(j - k) >= abs(j - B)) continue;
				dp[i + 1][k] = (dp[i + 1][k] + dp[i][j]) % mod; 
			}
		}
	}
	for (int i = 1; i <= N; i ++){
		ans += dp[N][i];
		ans %= mod;
	}
	printf("%lld\n", ans);

    return 0;
}