Number systems 2.11

Program The number system is designed to convert integers and fractional numbers from one positional number system with non-negative integer bases to another.
The range of numeral system values is from 2 to 36 inclusive. Numbers above 9 are indicated by Latin letters from A to Z. The case of the entered number does not matter. In the final number, the numbers-letters are displayed in uppercase.
It is possible to specify the accuracy of the output fractional number (for infinite periodic fractions). It is possible to check in the form of a reverse transfer - the back button. When translating negative numbers, the sign is preserved. The fractional part is separated from the whole by both a dot and a comma. The program does not allow entering more than one decimal point/comma. A dot is always added to the final number.
The program does not allow the input of invalid characters as well as invalid digits, which cannot be in this number system. For example, the digits 3 cannot be in a number that is specified in the binary number system.
When translating the integer part of numbers that is greater than 26 characters (in decimal equivalent) and when translating the fractional part of numbers that is greater than 26 characters (in decimal equivalent), errors are possible.