The below call option is European. What is the minimum arbitrage profit at time $T=1Y$

arising from the following prices?

$So=$$$19\mathrm{.}63$

$T=1Y$

$K=$$$18$

$c=$$$2\mathrm{.}77$

$r=6\%($cont$.$ comp. annual rate$)$

$($required precision $0\mathrm{.}01\frac{+}{-}0\mathrm{.}01)$