Calculating the Energy of Water Synthesis

The water synthesis reaction is written H2 + 1/2 O2 -> H2O (g). Given that E(H-H) = 436 kJ/mol, E(O=O) = 498 kJ/mol, and E(O-H) = 463 kJ/mol, calculate ΔrH for this reaction and state whether it is exothermic or endothermic.