input: 
  class Matrix:
      def __init__(self, m, n, lst):
          self.m = m
          self.n = n
          self.mat = []
  
          c = 0
          for i in range(self.m):
              a = []
              for j in range(self.n):
                  a.append(lst[c])
                  c += 1
              self.mat.append(a)
  
      def __str__(self):
          output = ""
          for i in self.mat:
              for j in i:
                  output += str(j) + " "
              output += '\n'
          return output
  
      def add(self, mat2):
          for i in range(self.m):
              for j in range(self.n):
                  self.mat[i][j] += mat2.mat[i][j]
  
      def sub(self, mat2):
          for i in range(self.m):
              for j in range(self.n):
                  self.mat[i][j] -= mat2.mat[i][j]
  
      def mul(self, mat2):
          result = []
          for i in range(self.m):
              a = []
              for j in range(mat2.n):
                  s = 0
                  for k in range(self.n):
                      s += self.mat[i][k] * mat2.mat[k][j]
                  a.append(s)
              result.append(a)
          self.mat = result
          self.m = len(result)
          self.n = len(result[0])
  
      def transpose(self):
          result = [[self.mat[j][i] for j in range(len(self.mat))] for i in range(len(self.mat[0]))]
          self.mat = result
          self.m = len(result)
          self.n = len(result[0])
  
  # Example usage:
  m1 = Matrix(2, 2, [1, 2, 3, 4])
  m2 = Matrix(2, 2, [5, 6, 7, 8])
  m1.add(m2)
  print(m1)  # Output expected: "6 8 \n10 12 \n"
  
output:     
      def scalar_mul(self, scalar):
          for i in range(self.m):
              for j in range(self.n):
                  self.mat[i][j] *= scalar
  
      def get_element(self, i, j):
          return self.mat[i][j]
  
      def set_element(self, i, j, value):
          self.mat[i][j] = value
  
      def is_square(self):
          return self.m == self.n
  
      def trace(self):
          if not self.is_square():
              raise ValueError("Matrix is not square")
          return sum(self.mat[i][i] for i in range(self.m))
  
      def is_symmetric(self):
          if not self.is_square():
              return False
          for i in range(self.m):
              for j in range(i + 1, self.n):
                  if self.mat[i][j] != self.mat[j][i]:
                      return False
          return True
  