Mirek's colleague bought a $1 "small science" apparatus at a flea market. It's a small box with two wires. The ends of these wires are almost connected, leaving a small distance l between them. If we connect the wires to a powerful voltage source, we can create a short electric arc. The sound of this discharge is quite loud, that's why Mirek's colleague uses this device as a lunch bell. Find the largest possible distance (in micrometers) of the wires that allows the creation of an electric discharge for a source with peak voltage 325V. The dielectric strength of air is D = 3 MV·m⁻¹.