When they added two more courses for the wall, the number of courses became 3+2 = <<3+2=5>>5
Since each course has 400 bricks, the total number of bricks for 5 courses is 5*400 = <<5*400=2000>>2000
To allow for an easy checkup of the wall, they removed 1/2*400 = <<1/2*400=200>>200 bricks from the last course of the wall.
In total, the wall has 2000-200= <<2000-200=1800>>1800 bricks.
#### 1800