//参考https://www.jianshu.com/p/90af98493661
while(str = readline()) {
    print(minDistance(str,readline())) // 2
}

function minDistance(s1, s2) {
    const len1 = s1.length
    const len2 = s2.length

    let matrix = []

    for (let i = 0; i <= len1; i++) {
        // 构造二维数组
        matrix[i] = new Array()
        for (let j = 0; j <= len2; j++) {
            // 初始化
            if (i == 0) {
                matrix[i][j] = j
            } else if (j == 0) {
                matrix[i][j] = i
            } else {
                // 进行最小值分析
                let cost = 0
                if (s1[i - 1] != s2[j - 1]) { // 相同为0,不同置1
                    cost = 1
                }
                const temp = matrix[i - 1][j - 1] + cost

                matrix[i][j] = Math.min(matrix[i - 1][j] + 1, matrix[i][j - 1] + 1, temp)
            }
        }
    }
    return matrix[len1][len2] //返回右下角的值
}