This paper studies the problem of deploying Unmanned Aerial Vehicles (UAVs) to augment cellular network capacity across diverse geographical regions. We formulate a comprehensive optimization problem, integrating considerations for the requisite number of UAVs, their strategic deployment locations, and the efficient allocation of resources. Initially, we estimate the optimal number of UAVs based on network scale. Subsequently, leveraging dynamic programming techniques, we address the challenges of UAV deployment and coverage radius determination. Association and power allocation are then performed based on the established deployment and coverage parameters. Through extensive simulations, we demonstrate the efficacy of our proposed UAV deployment strategy in significantly enhancing network utility and the served cellular user base.