input: Write a python function to find the length of the shortest common supersequence (SCS) of two strings.
  assert SCS("geek", "eke") == 5
  assert SCS("AGGTAB", "GXTXAYB") == 9
  assert SCS("abc", "ac") == 3
output: def SCS(str1, str2):
      m, n = len(str1), len(str2)
      
      # Create a table to store lengths of shortest common supersequences
      dp = [[0] * (n + 1) for _ in range(m + 1)]
      
      # Fill the table
      for i in range(m + 1):
          for j in range(n + 1):
              if i == 0:
                  dp[i][j] = j
              elif j == 0:
                  dp[i][j] = i
              elif str1[i - 1] == str2[j - 1]:
                  dp[i][j] = 1 + dp[i - 1][j - 1]
              else:
                  dp[i][j] = 1 + min(dp[i - 1][j], dp[i][j - 1])
      
      return dp[m][n]