#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 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 = 0; i < N; i ++){
		for (int j = 1; j <= N; j ++){
			// cout << i << " " << j << " " << dp[i][j] << ";;\n"; 
			if (j == B) continue;
			int st = j - abs(j - B) + 1;
			int en = j + abs(j - B) - 1;
			st = max(st, 1), en = min(en, N);
			// cout << st << " " << en << "[]\n";
			dp[i + 1][st] += dp[i][j];
			dp[i + 1][en + 1] -= dp[i][j];
			dp[i + 1][j] -= dp[i][j];
			dp[i + 1][j + 1] += dp[i][j];
			dp[i + 1][st] %= mod, dp[i + 1][en + 1] %= mod;
			dp[i + 1][j] %= mod, dp[i + 1][j + 1] %= mod;
		}
		for (int j = 1; j <= N; j ++){
			dp[i + 1][j] += dp[i + 1][j - 1]; // d_i -> a_i
			dp[i + 1][j] = ((dp[i + 1][j] % mod) + mod) % mod;
		}
	}
	for (int i = 1; i <= N; i ++){
		ans += dp[N][i];
		ans %= mod;
	}
	printf("%lld\n", ans % mod);

    return 0;
}