MathDB

Unique word !

Source: India TST 2001 Day 1 Problem 2

January 31, 2015

inequalitiescombinatorics proposedcombinatorics

Problem Statement

Two symbols

A

and

B

obey the rule

ABBB = B

. Given a word

x_1x_2\ldots x_{3n+1}

consisting of

n

letters

A

and

2n+1

letters

B

, show that there is a unique cyclic permutation of this word which reduces to

B