EnableExplicit
Macro putresult(n)
  If OpenConsole("Babbage_problem")
    PrintN("The smallest number whose square ends in 269696 is " + Str(n))
    Input()
  EndIf
EndMacro

CompilerIf #PB_Processor_x64
  #MAXINT = 1 << 63 - 1
CompilerElseIf #PB_Processor_x86
  #MAXINT = 1 << 31 - 1
CompilerEndIf

#GOAL = 269696
#DIV  = 1000000
Define n.i, q.i = Int(Sqr(#MAXINT))

For n = 2 To q Step 2
  If (n*n) % #DIV = #GOAL : putresult(n) : Break : EndIf
Next