If ReadFile(0,"in.txt")
  x$=ReadString(0)
  a=Val(StringField(x$,1," "))
  b=Val(StringField(x$,2," "))
  If OpenFile(1,"out.txt")
    WriteString(1,str(a+b))
    CloseFile(1)
  EndIf
  CloseFile(0)
EndIf