C++ :: Storing Multiple Arrays Based On User Input

I'm trying to create a function where it allows the user to type in multiple amounts of integers, so if the user wanted to have 3 different storages that hold different integers, the input would look something like this:

5
97 12 31 2 1 //let's say this is held in variable "a"
1 3 284 3 8 // "b"
2 3 482 3 4 // "c"
2 3 4 2 3 // "d"
99 0 2 3 42 // "e"

Since we don't know what number the user will input every time, I'm not sure how to create a dynamically allocated array that will create an x amount of arrays every time.. I want to be able to access each index of a, b, c, d, e or however many arrays there are.

So far, this is what I have, but I'm having trouble creating the arrays since it's unpredictable. I'm purposely not using vectors because I don't really get how pointers work so I'm trying to play around with it.

int* x;
int length, numbers;
cin >> length;
x = new int[length]
for (int i=0;i<length;i++)
{
cin >> numbers; //this doesn't work because it only grabs the first line for some reason
x[i] = numbers
}