echo Problem 1. Answer should be:
echo 1
echo 1
A 2 2
-1  1
 1 -1
done

echo Problem 2. Answer should be:
echo 1 0
echo 1 1
echo 0 1
A 1 3
1 -1 1
done

echo Problem 4. Answer should be:
echo <empty matrix>
A 1 2
1 1
done

echo Problem 5. Answer should be:
echo 1
echo 2
echo 2
echo 1
A 3 4
-1   0   1  -1
 2  -1   0   0
 0   1  -1   0
done
quit
