class Solution
{
    //Function to interchange the rows of a matrix.
    static void interchangeRows(int matrix[][])
    {
       for(int i=0;i<matrix.length/2;i++){
           for(int j=0;j<matrix[i].length;j++){
               int temp=matrix[i][j];
               matrix[i][j]=matrix[matrix.length-i-1][j];
               matrix[matrix.length-i-1][j]=temp;
           }
       } 
    }
}