Problem:
Score : 100 points

Problem Statement

Snuke lives at position x on a number line.
On this line, there are two stores A and B, respectively at position a and b, that offer food for delivery.

Snuke decided to get food delivery from the closer of stores A and B.
Find out which store is closer to Snuke's residence.

Here, the distance between two points s and t on a number line is represented by |s-t|.

Constraints

1 \leq x \leq 1000

1 \leq a \leq 1000

1 \leq b \leq 1000

x, a and b are pairwise distinct.

The distances between Snuke's residence and stores A and B are different.

Input

Input is given from Standard Input in the following format:

x a b

Output

If store A is closer, print A; if store B is closer, print B.

Sample Input 1

5 2 7

Sample Output 1

B

The distances between Snuke's residence and stores A and B are 3 and 2, respectively.
Since store B is closer, print B.

Sample Input 2

1 999 1000

Sample Output 2

A

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include "bits/stdc++.h"
using namespace std;

#define ASC(vec) vec.begin(), vec.end()		// 昇順ソート 例：sort(ASC(vec));
#define DESC(vec) vec.rbegin(), vec.rend()	// 降順ソート 例:sort(DESC(vec));
#define rep(i, n) for(int i = 0; i < n; i++)
#define Rep(i, n) for(int i = 1; i < n; i++)
#define In(vec) rep(i, n) cin>>vec[i];
#define ANS(s) cout << s << endl
#define inc(a, b) cin >> a >> b;

const int mod = 1000000007;
const int inf = (int)1e9 + 7;
const long long INF = 1LL << 60;

using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using vd = vector<double>;
using vvi = vector<vector<int>>;
using vii = vector<pair<int, int>>;

template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }

ll GCD(ll a, ll b) { return b ? GCD(b, a % b) : a; }
int round_int(int a, int b) { return (a + (b - 1)) / b; }


// 4,8方向に探索する際に用いる配列
//int dx[4] = { 0,  0, 1, -1 };
//int dy[4] = { 1, -1, 0,  0 };
//int dx[8] = { 1, 0, -1,  0, 1, -1, -1,  1 };
//int dy[8] = { 0, 1,  0, -1, 1,  1, -1, -1 };

constexpr auto MAX = 100010;

// ────────────────────────────────────────────────────

int main() {
	int x, a, b;
	cin >> x >> a >> b;
	if (abs(a - x) > abs(b - x)) cout << "B" << endl;
	else cout << "A" << endl;
}