/// 112 年工科賽第 2 題
/// 最小編輯距離
/// 漆家豪 於海青資訊科 2024/2/8
using System;

class EditDistance
{
    static int minDistance(string word1, string word2)
    {
        int m = word1.Length , n = word2.Length , i , j , cost;
        int[,] dp = new int[m + 1, n + 1];
        // 初始化第一列和第一行
        for (i = 0; i <= m; i++) dp[i, 0] = i;
        for (i = 0; i <= n; i++) dp[0, i] = i;
        // 填充動態規劃表格
        for (i = 1; i <= m; i++)
        {
            for (j = 1; j <= n; j++)
            {
                cost = (word1[i - 1] == word2[j - 1]) ? 0 : 2;
                dp[i, j] = Math.Min(Math.Min(dp[i - 1, j] + 1, dp[i, j - 1] + 1), dp[i - 1, j - 1] + cost);
            }
        }
        // 返回最終結果
        return dp[m, n];
    }

    static void Main()
    {
        string word1 = Console.ReadLine();
        string word2 = Console.ReadLine();
        int result = minDistance(word1, word2);
        Console.WriteLine(result);
    }
}