While walking and carrying a bag do you do work? my teacher says there is no work done be(look in the details)

coz d force is the part wer d arm is holdin the bag & since the bag isnt movin up (the direction of dat force), no work. but i say there is done work coz the force from my legs goes horizontaly & so does the bag (it goes to the direction of dat force see); plus, it was displaced from the original position its like |o........|o; where the person is the | and the bag is the o; see the displacement? its just like pushin the bag only its elevated; pushing and displacing something is definitely work!! then another of the explanations that says there is no work is that it wasn't dsplaced from your body itself. at dat time when that was said i was finaly convinced but wen she said walkin upstairs carryin a bag was doin work i got cnfused agen coz walkin upstairs definitely doesnt displace the bag from the body!! den she said walkin up & the bag goin up was work;dsplacement in direction of force, but isnt walkn horizontaly & the bag also goin der is also dsplacement in d direction of d force?