#include <iostream>
#include <cstring>
using namespace std;
int length,wide,N,step,pointer;
char ways[730];
bool  chessboard[35][35];
void push_way(int i,int j)
{
	ways[pointer++]=static_cast<char>(i+'A');
	ways[pointer++]=static_cast<char>(j+1+'0');
}
void pop_way()
{
	ways[pointer--]=0;
	ways[pointer--]=0;
}
int direction[8][2]={{-2,-1},{-2,1},{-1,-2},{-1,2},{1,-2},{1,2},{2,-1},{2,1}}; //字典序先往上头跳，再往下头跳
bool DFS(int i,int j)         
{
	if( i>=0 && j>=0 && i<wide && j<length && !chessboard[i][j] )
	{
		push_way(i,j);
		chessboard[i][j]=1;
		++step;
	}
	else return 0;
	if(step==length*wide)return 1;
	for (int ix=0;ix!=8;++ix)
	{
		int di=i+direction[ix][0];
		int dj=j+direction[ix][1];
		if(DFS(di,dj))return 1;
	}
	pop_way();
	chessboard[i][j]=0;
	--step;
	return 0;
}
int main()
{
	cin>>N;
	for(int ii=1;ii!=N+1;++ii)
	{
		step=0,pointer=0;
		memset(chessboard,0,sizeof(chessboard));
		memset(ways,0,sizeof(ways));
		cin>>length>>wide;
		if(DFS(0,0))cout<<"Scenario #"<<ii<<endl<<ways<<endl;
		else cout<<"Scenario #"<<ii<<":"<<endl<<"impossible"<<endl;
		cout<<endl;
	}
	return 0;
}

要疯了，要疯了~~~~~~~~~~