input: from typing import List
  
  def edit_distance(s1: str, s2: str) -> int:
      """Compute the edit distance between two strings.
      
      >>> edit_distance("kitten", "sitting")
      3
      """
      m, n = len(s1), len(s2)
      dp = [[0] * (n + 1) for _ in range(m + 1)]
  
      for i in range(m + 1):
          dp[i][0] = i
      for j in range(n + 1):
          dp[0][j] = j
  
      for i in range(1, m + 1):
          for j in range(1, n + 1):
              if s1[i - 1] == s2[j - 1]:
                  dp[i][j] = dp[i - 1][j - 1]
              else:
                  dp[i][j] = 1 + min(dp[i - 1][j], dp[i][j - 1], dp[i - 1][j - 1])
      
      return dp[m][n]
output:     m, n = len(s1), len(s2)
      dp = [[0] * (n + 1) for _ in range(m + 1)]
  
      for i in range(m + 1):
          dp[i][0] = i
      for j in range(n + 1):
          dp[0][j] = j
  
      for i in range(1, m + 1):
          for j in range(1, n + 1):
              if s1[i - 1] == s2[j - 1]:
                  dp[i][j] = dp[i - 1][j - 1]
              else:
                  dp[i][j] = 1 + min(dp[i - 1][j], dp[i][j - 1], dp[i - 1][j - 1])
      
      return dp[m][n]