Amongest the following the total number of compounds which does not give Lassaigne’s test for nitrogen 

i)    ii) $H_{2}N-C{H}_2-COOH$    iii)  $H_{2}N-N{H}_2$     iv) $H_{2}N-OH$      v) Urea 

vi) $PhN{O}_2$       vii)  $C{H}_{3}CHO$      viii) $C{H}_{3}CN$