m = len(s1)

n = len(s2)

dp = [[None] * (n + 1) for i in range(m + 1)]

for row in range(m + 1):

for col in range(n + 1):

if row == 0:

dp[row][col] = col

elif col == 0:

dp[row][col] = row

elif s1[row - 1] == s2[col - 1]: # If both strings are equal no operation is required

dp[row][col] = dp[row - 1][col - 1]

else: # Get one plus min of insert, delete, replace

dp[row][col] = min(dp[row - 1][col - 1], dp[row - 1][col], dp[row][col - 1]) + 1

return dp[m][n]

'''