题目描述
Problem Statement
We have an empty box.
Takahashi can cast the following two spells any number of times in any order.
- Spell A: puts one new ball into the box.
- Spell B: doubles the number of balls in the box.
Tell us a way to have exactly N balls in the box with at most $\mathbf{120}$ casts of spells.
It can be proved that there always exists such a way under the Constraints given.
There is no way other than spells to alter the number of balls in the box.
Input
Input is given from Standard Input in the following format:
N
Output
Print a string S consisting of A and B.
The i-th character of S should represent the spell for the i-th cast.
S must have at most $\mathbf{120}$ characters.
Constraints
- $1 \leq N \leq 10^{18}$
- All values in input are integers.
Sample Input 1
5
Sample Output 1
AABA
This changes the number of balls as follows: $0 \xrightarrow{A} 1\xrightarrow{A} 2 \xrightarrow{B}4\xrightarrow{A} 5$.
There are also other acceptable outputs, such as AAAAA.
Sample Input 2
14
Sample Output 2
BBABBAAAB
This changes the number of balls as follows: $0 \xrightarrow{B} 0 \xrightarrow{B} 0 \xrightarrow{A}1 \xrightarrow{B} 2 \xrightarrow{B} 4 \xrightarrow{A}5 \xrightarrow{A}6 \xrightarrow{A} 7 \xrightarrow{B}14$.
It is not required to minimize the length of S.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分