Given the following reactions

$F{e}_2{O}_3(s)+3CO(g)2Fe()+3C{O}_2(g),H=-28\mathrm{.}0kJ$

$3Fe(s)+4C{O}_2(g)4CO(g)+F{e}_3{O}_4(),H=+12\mathrm{.}5kJ$

the enthalpy of the reaction of $F{e}_2{O}_3$ with $CO$

$3Fen{O}_3(s)+CO(Q)CO(Q)+2FeB{O}_4(s)$