Uglies 01 by Scott Westerfeld

The provided text introduces Tally Youngblood, an "ugly" teenager living in a futuristic society where everyone undergoes a mandatory operation at sixteen to become "pretty." Eager for her own transformation, Tally's plans are disrupted when she befriends Shay, who plans to run away to a hidden community called the Smoke, where people choose to remain "ugly." Tally is coerced by a special authority called Special Circumstances to betray the Smoke in exchange for her pretty operation, leading her on a journey where she discovers the dark secrets behind the pretty regime and the true meaning of beauty and freedom alongside a runaway named David. Ultimately, Tally must make a difficult choice that will impact her future and the fate of those who reject the city's superficial perfection.