#include <bits/stdc++.h>
using namespace std;
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(0);
  int t, i, n, j, e;
  char grid[8][8];
  map<int, bool> black, white;
  for (i = 0; i < 8; i++) {
    cin >> grid[i];
  }
  int min = INT_MAX;
  int flag = 0;
  for (i = 0; i < 8; i++) {
    for (j = 0; j < 8; j++) {
      if (grid[i][j] == 'W') {
        int x = i;
        int y = j;
        int f = 1;
        while (x >= 0) {
          if (grid[x][j] == 'B') {
            f = 0;
            break;
          }
          x--;
        }
        if (f == 1) {
          if (min >= i) {
            min = i;
            flag = 0;
          }
        }
      }
      if (grid[i][j] == 'B') {
        int x = i;
        int y = j;
        int f = 1;
        while (x < 8) {
          if (grid[x][j] == 'W') {
            f = 0;
            break;
          }
          x++;
        }
        if (f == 1) {
          if (min > (7 - i)) {
            min = 7 - i;
            flag = 1;
          }
        }
      }
    }
  }
  if (flag == 0)
    cout << "A";
  else
    cout << "B";
  return 0;
}
