Doubt Array Solidity

Question

I am trying to assign the value of an array to two arrays, as follows:

pragma solidity ^0.4.24;
pragma experimental ABIEncoderV2;

contract ArrayExamples {

    int[][] public matriz;


    // Os dados são recebidos da seguinte forma: [0,0]
    function receive_data(int[] data) public {
        matriz.push(data);
    }


    function teste() public returns (int[] v) {

        int[] x;
        int[] y;

        uint t = matriz.length;

        for(uint i = 0; i < t; i++) {

            x[i] = matriz[i][0];
            y[i] = matriz[i][1];

        }

        return x;
    }

  }

The matrix is dynamic, but in the example above it takes as default an array with two elements. [0,0]

When I assign the values of x and y is not, only the values of y are assigned correctly. x is responsible for taking only the first value of the dynamic array and y takes the last value.

When will I check the value of x, it is said that it took the last value of the dynamic array, and it should take the first value of the array.

If I enter the following array: [4,5] - both x, how much y take 5, and x should take 4.