Let α be a root of the equation x2+x+1=0 and the matrix
A=⎡⎢⎣1111αα21α2α4⎤⎥⎦ then the matrix A31 is equal to
A=⎡⎢⎣112021102⎤⎥⎦and A3=(aA−I)(bA−I), where a, b are integers and I is a 3×3 unit matrix then value of (a + b) is equal to