A12556. Game 23
编程题
普及/提高-
知识点
题目描述
Polycarp plays "Game 23". Initially he has a number $n$ and his goal is to transform it to $m$ . In one move, he can multiply $n$ by $2$ or multiply $n$ by $3$ . He can perform any number of moves.
Print the number of moves needed to transform $n$ to $m$ . Print -1 if it is impossible to do so.
It is easy to prove that any way to transform $n$ to $m$ contains the same number of moves (i.e. number of moves doesn't depend on the way of transformation).
Print the number of moves needed to transform $n$ to $m$ . Print -1 if it is impossible to do so.
It is easy to prove that any way to transform $n$ to $m$ contains the same number of moves (i.e. number of moves doesn't depend on the way of transformation).
输入格式
The only line of the input contains two integers $n$ and $m$ ( $1 \le n \le m \le 5\cdot10^8$ ).
输出格式
Print the number of moves to transform $n$ to $m$ , or -1 if there is no solution.
输入输出样例
输入 #1
120 51840
输出 #1
7
输入 #2
42 42
输出 #2
0
输入 #3
48 72
输出 #3
-1
说明/提示
In the first example, the possible sequence of moves is: $120 \rightarrow 240 \rightarrow 720 \rightarrow 1440 \rightarrow 4320 \rightarrow 12960 \rightarrow 25920 \rightarrow 51840.$ The are $7$ steps in total.
In the second example, no moves are needed. Thus, the answer is $0$ .
In the third example, it is impossible to transform $48$ to $72$ .
In the second example, no moves are needed. Thus, the answer is $0$ .
In the third example, it is impossible to transform $48$ to $72$ .