The RBC Heritage Classic Foundation license plate is available to anyone with a vehicle registered in the state of South Carolina. It costs $75 every two years with $66 to $71 going to the foundation for its Scholar and Birdies for Charity Programs. The plate has the Heritage Classic symbol and four spaces for nonzero digits and/or letters. How many possible plates can be produced using from 1 to 4 digits or letters if they can be repeated?