Let f $=(16,14,16,14,4,6,4,6)^$T be a discrete signal. The Discrete Fourier Transform $($DFT$)$ of f is given by u $=($u$0,$ u$1,$ u$2,$ u$3,$ u$4,$ u$5,$ u$6,$ u$7)^$T$.$

a$)$ Which coefficient corresponds to the highest frequency?