Bagels 1.0

Based on one of Jim Butterfield's ML games for the KIM-1. The computer randomly chooses 4 letters, between A - F. You must type in the four letters in order to guess the hidden code. The computer will show a number in two columns on the right hand side. The right letter, but in the wrong place, or a number of letters that are in the correct place. These are marked as EXA and MUTE. After your complete the first code. You can work on the next one. Somewhat similar to Mastermind.