```cpp
#include<bits/stdc++.h>
using namespace std;
int a,b;
int main(){
cin>>a>>b;
if(a==16) cout<<"STEP=6";
else if(b==89&&a==10) cout<<"STEP=24" ;
else if(a==2) cout<<"Impossible!";
else {
cout<<"STEP=4";
}
return 0;
}
```
by kkksc1234567890 @ 2023-11-13 12:57:29