This paper proposes a simple and efficient method for training a value model for long contextual inference traces. Unlike the existing Process Reward Model (PRM), our method does not require a fine-grained concept of "steps," which are difficult to define in long contextual inference models. We trained a value model at the 1.5 billion token level using a dataset of 2.5 million inference traces and applied it to the DeepSeek model to improve performance through test-time computational scaling. We found that using Block-wise Value-Guided Search (VGS) with final weighted majority voting outperforms standard methods such as simple majority voting or best-of-n in terms of test-time scaling. Furthermore, VGS significantly reduces the inference FLOPs required to achieve the same performance as majority voting. The dataset, model, and codebase are publicly available.