#include<bits/stdc++.h> using namespace std; void f(int n,char q,char c,char z){ if(n==1) cout<<q<<" To "<<z<<endl; else{ f(n-1,q,z,c); cout<<q<<" To "<<z<<endl; f(n-1,c,q,z); } } int main(){ int n; cin>>n; f(n,'A','B','C'); } /************************************************************** Problem: 1222 User: linweilun Language: C++ Result: Accepted Time:9 ms Memory:2072 kb ****************************************************************/