def determine_winner():
    max_n = 100
    grundy = [0] * (max_n + 1)
    grundy[1] = 0  # 1 stones cannot split, lose immediately
    
    for n in range(2, max_n + 1):
        moves = set()
        
        # Check 2-split possibilities
        if n % 2 == 0:
            x = n // 2
            if x >= 1:
                # Split into two parts x, x
                g = grundy[x] ^ grundy[x]
                moves.add(g)
        else:
            x = (n - 1) // 2
            if x >= 1:
                # Split into x and x+1
                g = grundy[x] ^ grundy[x + 1]
                moves.add(g)
        
        # Check 3-split possibilities
        if n >= 3:
            # Case 3x
            if n % 3 == 0:
                x = n // 3
                if x >= 1:
                    g = grundy[x] ^ grundy[x] ^ grundy[x]
                    moves.add(g)
            # Case 3x + 1
            if (n - 1) % 3 == 0:
                x = (n - 1) // 3
                if x >= 1:
                    g = grundy[x] ^ grundy[x] ^ grundy[x + 1]
                    moves.add(g)
            # Case 3x + 2
            if (n - 2) % 3 == 0:
                x = (n - 2) // 3
                if x >= 1:
                    g = grundy[x] ^ grundy[x + 1] ^ grundy[x + 1]
                    moves.add(g)
        
        # Calculate mex for current n
        mex = 0
        while True:
            if mex not in moves:
                grundy[n] = mex
                break
            mex += 1
    
    n = int(input())
    return 'A' if grundy[n] != 0 else 'B'

print(determine_winner())