If I Exchange My Coat for Straw Sandals, I Will Lose Hundreds of Billions of Supplies Until I Die!

[Resource exchange + Helping ancestors + Fun-paced writing + Historical era] My grandma talks to me about my grandpa whom I have never met, and she always looks proud. She tells me that your grandpa is a hero! So, I opened the exchange point on my grandfather's only route. In the violent storm, he stood outside the glass door, looking at the steaming heat in the store, and did not dare to open the door. I smiled and opened the door: "Comrade, do you want to come in and have a bowl of noodles?" He shook his head and muttered: "It must be a trap, trying to get my information!" I also smiled: "Can you sing? If you can sing, you can eat for free!" …