Thank you, graff, it was what I mean. I thought it must DWIM, and "use bigint" must not work in different way from "use bigint". I found real number instead of integer in this case at the bottom, later wrote here. 
use bigint;
($m,$k)=split/ /,<>;
print $k<$m? $m / ++$k : -1

[download]
stdin="10 2\n" stdout=3.33... One more strange is that increment of "2\n" did not change it to a number.

In reply to Re^2: is it a BigInt bug? by rsFalse
in thread is it a BigInt bug? by rsFalse

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