input: def editDistance(string1: str, string2: str, m: int, n: int) -> int:
      """
      Compute the edit distance between two strings.
      >>> editDistance("kitten", "sitting", 6, 7)
      3
      >>> editDistance("eagle", "angle", 5, 5)
      2
      """
      dp = [[0 for x in range(n+1)] for x 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 string1[i-1] == string2[j-1]:
                  dp[i][j] = dp[i-1][j-1]
              else:
                  dp[i][j] = 1 + min(dp[i][j-1],        # Insert
                                     dp[i-1][j],        # Remove 
                                     dp[i-1][j-1])      # Replace
      return dp[m][n]
output:     dp = [[0 for x in range(n+1)] for x 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 string1[i-1] == string2[j-1]:
                  dp[i][j] = dp[i-1][j-1]
              else:
                  dp[i][j] = 1 + min(dp[i][j-1],        # Insert
                                     dp[i-1][j],        # Remove 
                                     dp[i-1][j-1])      # Replace
      return dp[m][n]