Consider the matrices: 
. Let the set of all \( m \), for which the system of equations \( AX=B \) has a negative solution (i.e., \( x<0 \) and \( y<0 \)), be the interval \( (a,b) \). Then \(\displaystyle 8\int_{a}^{b}\lvert A\rvert\,dm \) is equal to ________.
