Problem Description

Implement a string compression algorithm using run-length encoding. Compress consecutive identical characters into the format "character + count". If compression doesn't reduce length, return original string.

Input Format

A single string containing letters.

Output Format

Compressed string if shorter, otherwise original string.

Constraints

• 1 ≤ string length ≤ 1000

• String contains only uppercase and lowercase letters

• Format: character followed by count (e.g., a3b2c1)

• Single characters become char1 (e.g., a becomes a1)

• Return original if compressed is not shorter

Sample Input/Output

aabcccccaaa

a2b1c5a3

Explanation

Original: "aabcccccaaa" (11 chars). Compressed: "a2b1c5a3" (8 chars). Compression is shorter, so return compressed.