import std.algorithm, std.container, std.conv, std.math, std.range, std.typecons, std.stdio, std.string;

auto rdsp(){return readln.splitter;}
void pick(R,T)(ref R r,ref T t){t=r.front.to!T;r.popFront;}
void readV(T...)(ref T t){auto r=rdsp;foreach(ref v;t)pick(r,v);}

void main()
{
  int n; readV(n);

  auto g = new int[](n+1);
  foreach (i; 2..n+1) {
    auto mex = new bool[](n+1);
    foreach (a; 1..i) {
      auto b = i-a;
      mex[g[a]^g[a]] = true;
    }
    foreach (a; 1..i-1)
      foreach (b; 1..i-1) {
        auto c = i-a-b;
        if (c <= 0) break;
        mex[g[a]^g[b]^g[c]] = true;
      }
    g[i] = mex.countUntil(false).to!int;
  }

  writeln(g[n] == 0 ? "B" : "A");
}