=(121121*1000001)/(212121*1000001)*(121212*100001)/(212212*1000001)
=121121/212121*121212/212212
=(121*101)/(21*10101)*(12*10101)/(212*101)
=(121)/(21)*(12)/(212)
=121*12/21/212
=121/7/53
=121/371