The Input N is what number system you are inputting. The output N is what number system you want it to become. For example Input N = 10 and Output N = 2 would translate the input in decimal (10) to binary (2).
The numbers (Input N and Output N) are the number of symbols that can used to describe a number. For example decimal is 10 because it uses 10 symbols: 0,1,2,3,4,5,6,7,8,9. Some systems use Letters instead where A = 10, B = 11, and so forth. The way all of these number systems work is fairly simple. We all understand the decimal system so well you don't even have to think about it. But all of these number systems follow the same exact pattern as the decimal system with one major difference: the base. What I mean is this. To calculate the value of any position in a decimal number you follow a formula: x * 10^n where x is the value and n is the position with the rightmost being zero and increasing as you go to the left. You may have noticed that the base of the power expression 10^n is 10. This is not a coincidence. The base is always equal to the number of symbols used in the system. For example the base is 2 for binary and 16 in hexadecimal. This algorithm will allow you to use numbers that aren't in the inputs number system I don't know what will happen exactly but you can do that.
