Please choose the correct ending to complete the given sentence: Health: [header] How to disinfect drinking water in the wilderness [title] Pack the proper water purifying equipment and chemicals. [step] If you're backpacking you should have a high quality pump with a filter, and/or purifying tablets. [title] Immerse the end of the pump where water flows in in the clearest portion of the water source that you can see.

Ending1: [title] Submerge the end of the pump (the end labeled " water source ") in lukewarm water for at least an hour or two. [title] Squeeze several tablespoons of distilled water over the end of the pump. Ending2: [title] Use the pump's plug to compress water running into your opening. [title] Soak for at least 72 hours if you're doing it out in a helicopter. Ending3: [step] It's a good idea to hose the end dry to avoid diluting the water further as you go. [title] Keep the pump as far away from humans as possible while working. Ending4: [step] Deeper areas are preferable since it will be easier to draw out water. [title] Pump until your water container is full.

Answer format: ending1/ending2/ending3/ending4