After the apocalypse began, I followed my father's last instructions and found a fortress inside a mountain. There was enough food, water, and power to last ten years, but my father had been one of the people who developed the doomsday virus. A little girl with a severed hand knocked at the door, begging for help. A hunter behind her chambered a round. In the snow, a mother crawled toward the fortress. My father had said, “All you have to do is survive.” But when I used my fingerprint to open the door, I discovered that the way he wanted me to survive was nothing like I'd imagined.
The logic is clear, the plot is compact, and the description is clear.
The plot is full of ups and downs, not bloody, and the male protagonist is decisive enough, not a virgin.