Get x,y //x,y any numbers
set gcd to 0 //gcd = Great Common divisor
if (x>0) and (y>0)
   then if (x-y) > 0
             then while (x>y)
                    { set gcd to ( gcd + (x-y) )
                       set x to x-y
                     }
                     print " the GCD" + gcd
              else if (y-x) > 0
                    then while (y>x)
                           { set gcd to ( gcd + (y-x) )
                             set y to (y-x)
                            }
                            print "the GCD "+ gcd
                      else print " the numbers are equal"
                      end if 
               end if
   else print " There is a negative number at least "
end if