Computing the final 2D point reached by extremely long walks for g85 and g98

m85[0] = {1, 0, 0, 0} ; m85[n_] := m85[n] = (19 21 27 18) . m85[n - 1]  ... f85[x_] := (-1 1 0 0 ) . m85[x] ;  0 0 -1 1 f85[50] f98[50]

{-26861798920761329483935266043759272105572916028, 26860000455718682071788645763418702456223664779}

{-3590203562305615923791774142984724747568191373312, 3588776314612909963910715857015275252431808626688}

g85Distance[n_] := Sqrt[f85[n][[1]]^2 + f85[n][[2]]^2] g98Distance[n_] := Sqrt[f98[n][[1]]^2 + f98[n][[2]]^2]

Created by Mathematica  (February 18, 2004)