question: private int heightOfPhi ( int Phi ) { if ( Phi == 0 ) { return - 1 ; } int Tau = 0 ; int modul = 1 ; while ( Phi % modul == 0 ) { modul *= 2 ; Tau += 1 ; } return Tau - 1 ; }
target:  Returns the largest h such that 2^h | Phi