In X[3][3], the array elements are actually x[0][0],x[0][1],x[0][2],x[1][ 0],x[1][1],x[1][2],x[2][0],x[2][1],

x[2][2]. So 1,2,3,4,5,6,7,8,9 are assigned to x[0][0],x[0][1],x[0][2],x[1] [0],x[1][1],x[1][2],

x[2][0],x[2][1],x[2][2] these nine elements.