Molality of pure water is__?

$molality=\frac{weightofsolute\times 1000}{grammolecularweight\times weightofsolventingram}$

One litre of water has mass = 1000 gram because density of water is 1gram/ml therefore 1 gram = 1 ml

 $m =\frac{1000}{18}\times \frac{1000}{1000}=55.56$