Mountains and Foggy Fields

She is a forest ranger who has been guarding alone in the mountains for twenty years. Every morning, she calls out to the mountains, "Mountains face foggy fields" - this is the secret code for her and her late husband, who was a geological team member and disappeared in this mountain forest. That year of heavy fog, she finished shouting as usual, and suddenly heard an echo from the distance: "Ye Chao Mountain." She was stunned, stumbled and ran over, and saw an old man with white hair leaning on a branch and holding a piece of ore in his arms. He said: "I was lost for twenty years, and I only found my way home when I heard your voice." She rushed towards him and beat him, crying: "Do you know how many times I shouted? Seven thousand three hundred times."