vô tư 
impartial, unbiased [ vô ] : (1) in-, im-, (negative prefix); (2) in, at, on; (3) to go into, enter [= vào]
[ tư ] : (1) four (in compound numbers); (2) private, personal; (3) capital
Most Common Compounds Set 1:
Most Common Compounds Set 2 :
vô tư