From the roots of the quadratic equation given below, the larger root is ‘a’ and the smaller root is ‘b’.

Quadratic equation: x² - 39x + 324 = 0

(i) Subtract 5 from ‘a’ and put the resultant number in LHS of the quadratic equation to get the value of ‘m’

(ii) Subtract 2 from ‘b’ and put the resultant number in LHS of the quadratic equation to get the value of ‘n’

What is the sum of ‘m’ and ‘n’?