//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
}