Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to clean a headphone jack [title] Buy a can of compressed air. [step] These cans can often be found at electronics stores like radioshack or best buy. Compressed air is also used for clearing debris from computer parts, so look where computer parts are sold.

Ending1: [substeps] If you have a standalone cooler, squeeze it as much as possible against a hard surface in order to extract the compressed air, but don't worry if there is air left behind. It should have made contact with the glass front of the cooler. Ending2: [title] Pour compressed air onto a cloth or a newspaper. [step] Roll up the cloth or newspaper several times over the freshly-collapsed headphone jack. Ending3: Air is least likely to damage your jack since you don't have to put anything inside the hole other than the air. [title] Point the nozzle at the headphone jack. Ending4: You may need a few dozen cans or so. [substeps] Don't use a metal can.

Answer format: ending1/ending2/ending3/ending4