while True:
    try:
        s1, s2 = input(), input()
        n1, n2 = len(s1), len(s2)
        # 初始化数组dp
        dp = [[0] * (n2+1) for _ in range(n1+1)]
        # 初始化边界
        for i in range(1, n2+1):
            dp[0][i] = i
        for i in range(1, n1+1):
            dp[i][0] = i
        # 遍历两个字符串
        for i in range(1, n1+1):
            for j in range(1, n2+1):
                if s1[i-1] == s2[j-1]:
                    dp[i][j] = dp[i-1][j-1]
                else:
                    dp[i][j] = min(dp[i-1][j-1], dp[i-1][j], dp[i][j-1]) + 1
        print(dp[n1][n2])
    except:
        break