The mathematical conversion is somewhat complex and best left to a computer, but it’s notable that the WIF guarantees it will always correspond to the same address no matter which program is used to convert it. Do not send bitcoins to or import any sample keys; you will lose your money. They consist of random digits and uppercase and lowercase letters, with the exception that the uppercase letter “O”, uppercase letter “I”, lowercase letter “l”, and the number “0” are never used to prevent visual ambiguity. Like e-mail addresses, you can send bitcoins to a person by sending bitcoins to one of their addresses.