第一次比赛题目二

A. Game 23
time limit per test1 second
memory limit per test256 megabytes
inputstandard input
outputstandard output
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).

Input
The only line of the input contains two integers n and m (1≤n≤m≤5⋅108).

Output
Print the number of moves to transform n to m, or -1 if there is no solution.

Examples
inputCopy
120 51840
outputCopy
7
inputCopy
42 42
outputCopy
0
inputCopy
48 72
outputCopy
-1
Note
In the first example, the possible sequence of moves is: 120→240→720→1440→4320→12960→25920→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.

值得注意的是

• 超时 单是除会超时，那么应该如何去简化算法呢？

#include
using namespace std;
int main()
{
     int n,m;
     cin>>n>>m;
     
     if(m%n==0)
     {
     int cishu=0;
     int k=m/n;
      while(k%2==0)
      {chishu++;k=k/2;}
      while(k%3==0)
     {cishu++;k=k/3;}
     if(k==1)
     {cout<

把2全除尽
把3全除尽
就是这样......