The question says that the end of the cave is 380 meters below.
Lets say the sea level or the surface is at 0 meters or we can say that it is the reference level for us.
Now if we go up the height will be measured with positive integer but if we go down the depth will be represented by a negative integer.
Negative integer also represents the depth or the distance below the surface level.
Here we need to generate an integer that can represent the depth of 380 meters.
So if we are going down we will use negative integer to represent.
Therefore, the integer to represent the depth is meters.