On January 3, in a temporary garrison on the border of Yunnan, officers and soldiers of a mine-clearing and explosive disposal brigade of the southern theater army were busy in an orderly and tense manner. Today, they are about to go to the minefield to start the new year's mine clearance and explosive disposal operation. At this time, the instructor Huang Jianjun's mobile phone rang. It turned out that Du Fuguo, who was on vacation in his hometown in Guizhou, made a voice call. "Instructor, today we are going to go to the minefield again. Please help me convey to my comrades that we must pay attention to safety when clearing mines..." The familiar voice of Du Fuguo, the "hero of mine clearance", came from the phone. Hearing Du Fuguo's greetings, Chen Zihan, Liu Xinwei, Xiong Xin and other comrades-in-arms who had joined the brigade and fought side by side with him felt warm. The minefield is getting closer. Following Du Fuguo's battle trail, the heroic demining soldiers set foot on the "battlefield" again. Since the day I joined the brigade, I have made the worst plan for mine clearance. When I input these two words into the search engine, the first thing that pops up is a computer game. In this computer game, players need to find all the spaces without mines in the shortest time. The rules of the game are not complicated. Players should try like a blind box - even if the location of the mines can be inferred from the numbers, no one can accurately know whether there are mines in the grid before clicking. This is similar to mine sweeping in reality, but the reality is far more complicated than the game. There is no obvious sign data in the real minefield, and there is no chance of "coming back after death". It was a summer afternoon four years ago. When the leaves were removed, Sergeant Chen Zihan obviously felt his heart beating faster and his hands were tense. A cannonball inserted obliquely at the root of a big tree came into sight, and the tail wing exposed to the ground was already rusty. This is a heavy mortar shell, which does not explode after firing, and its performance is extremely unstable. It may explode at the slightest touch. The performance of a series of related parameters jumped into Chen Zihan's mind. As a veteran who came to the brigade with Du Fuguo, he has rich experience in mine clearance and explosive disposal. At the moment, Chen Zihan knew better than anyone that if this shell had an accident, he and his comrades would be in danger. The best way to ensure safety is to stay away from danger. However, in order to protect the people in the border areas from landmines, Chen Zihan and his comrades had to approach these dangerous sources and dispose of explosives time and time again. "Everyone stop working and exit the passage!" Chen Zihan turned his head and gave instructions to his comrades in the search platoon next to him. When his comrades retreated to the safety zone, he took a deep breath and began to dig. The excavation operation is not smooth. It has just rained. It is easy to stick soil on the excavation tools. In order to ensure safety, Chen Zihan had to use his hands to remove the soil from the tools every time he dug, and the progress was very slow. After finishing the excavation work, the situation in the mine pit made Chen Zihan feel numb for a while - the shell was more than one meter long, the shell bowl mouth was thick and thin, and was wrapped by four roots more than 10 cm thick. In this case, the safest way to deal with it is not to touch the unexploded ordnance and directly detonate it with explosives. However, this kind of disposal is no longer possible, because a few meters away is the border line. Chen Zihanzhi