Hot and cold fluids enter a parallel flow double tube heat exchanger at 100^oC and 15^oC, respectively. The heat capacity rates of hot and cold fluids are C_h = 2000 W/K and Cc = 1200 W/K, respectively. If the outlet temperature of the cold fluid is 45^oC, the log mean temperature difference (LMTD) of the heat exchanger is ________ K (round off to two decimal places).