.model small
.stack 100h
.data
a1  dw  1
b1  dw  2
c1  dw  3
res dw  0

.code
Start:
  mov ax, @data
  mov ax, b1
  cmp ax, a1
  jg metka1
metka1:
  mov ax, c1
  cmp ax, b1
  jg metka2
metka2:
  mov ax, res
  add ax, 1
  mov res, ax
  int   21h
  end   Start