class Pairs {
   public static void main(String args[]) throws Exception
   {
 
      int mat[][]={{3, 5},
                  {6, 9},
                  {7, 5},
                  {7, 6},
                  {3, 9}};
 
      int i, j, k, row, col, r, temp, num;
      row = 5;
      col = 2;
 
      for (i = 0; i < row-1; i++) {
         num = mat[i][1];
         r = i;
         for (j = i+1; j < row; j++)
            for (k = 0; k < col; k++)
               if (num == mat[j][k])
                  r = j;
 
         temp = mat[i+1][0];
         mat[i+1][0] = mat[r][0];
         mat[r][0] = temp;
 
         temp = mat[i+1][1];
         mat[i+1][1] = mat[r][1];
         mat[r][1] = temp;
 
         if (mat[i+1][1] == num) {
            mat[i+1][1] = mat[i+1][0];
            mat[i+1][0] = num;
         }
 
      }
 
      for (i = 0; i < row; i++) {
         for (j = 0; j < col; j++)
            System.out.print(mat[i][j] + " ");
         System.out.println();
      }
 
   }
}