ruby module and mixin -- (multiple inheritance) -> same method name override

kk.rb

#!/usr/bin/env ruby


module A
   def a1
		 p "a1"
   end
   def a2
		 p "a2"
   end
end
module B
   def a1
		 p "b1"
   end
   def a2
		 p "b2"
   end
end

class Sample
include A
include B
   def s1
		 p "s1"
   end
end

samp=Sample.new

# FIXME how to call method A's method a1 instead of module B's method ?
samp.a1 # want to call module A's method a1
samp.a2 # want to call module A's method a2

samp.a1 # call module B's method a1
samp.a2 # call module B's method a1
samp.s1