How many kilograms of water can be heated through 30�C by a 17 kiloton atomic bomb.?

the kiloton which is used to measure the energy released in an atomic explosion, is equal to 4.2 multiplied by 1012 J (approximately the energy released in the explosion of 1000 tons of TNT). Recalling that 1 kilocalorie of energy raises the temperature of 1 kg of water by 1�C and that 4184 joules is equal to 1 kilocalorie, calculate how many kilograms of water can be heated through 30�C by a 17 kiloton atomic bomb.