void main()
main: scope:[main]  from
  [0] *b = 'c'
  [1] *SCREEN = *b
  [2] *(SCREEN+1) = *(c+1)
  [3] *(SCREEN+2) = *(d+2)
  to:main::@return
main::@return: scope:[main]  from main
  [4] return 
  to:@return