2002 KJMO P4
Source: KJMO 2002
June 29, 2024
number theory
Problem Statement
For two non-negative integers , create a new integer defined as the following: Express the two numbers in base , and compare each digit. If their th digit is the same, then the th digit of is . If their th digit is different, then the th digit of is (of course we are talking in base ). For instance, . Show that for arbitrary positive integer , the number can be expressed with finite operations of s and integers of the form .