100 cls
110 a = 40902
120 b = 24140
130 print : print "GCD(";a;", ";b;") = ";gcdi(a,b)
140 print : print "GCD(";a;", 111) = ";gcdi(a,111)
170 end

190 sub gcdi(x,y)
200  while y
210   t = y
220   y = x mod y
230   x = t
240  wend
250  gcdi = x
260 end sub