How to calculate the number after the dot in the national patent number?

When applying for a patent, there is a patent application number. If authorized, add "ZL" before the number to become the patent number. The last digit of the patent application number is a check bit, which is used to check whether the application number is correct. The formula is: s = x4 * 2+x3 * 3+x2 * 4+x1* 5+y * 6+z7 * 7+z6 * 8+z5 * 9+z4 * 2+z3 * 3+z2 * 4+z/kloc-0. For example, the application number is 201710601862.3, and the calculation method of parity bit is: (2 * 2+0 * 3+1* 4+7 * 5+1* 6+0 *.