void hanoi(int n,char a,char b,char c){
if(n == 1){
printf("%c -- %c\n",a,b);
}
else{
hanoi(n-1,a,c,b);//往左移动
printf("%c -- %c\n",a,b);
hanoi(n-1,c,b,a);//往右移动
}
}
int main(){
int n;
scanf("%d",&n);
hanoi(n,'a','b','c');
}