// 字符串解密
    func HW2023021() {
        // 测试用例
//        let inputStr1 = "123admyffc79pt", inputStr2 = "ssyy"
//        let inputStr1 = "123admyffc79ptaagghi2222smeersst88mnrt", inputStr2 = "ssyyfgh"
//        let inputStr1 = "abcmnq", inputStr2 = "rt"
        // 开始代码
        let inputStr1 = String(readLine()!)
        let inputStr2 = String(readLine()!)
        let diffLen = Set(Array(inputStr2)).count // 参考字符不同字母数量
        var resDic: [String: Int] = [:]           // 有效字符串保存字典
        var temp: String = ""                     // 临时字符串记录有效字符串
        var maxLen = 0                            // 有效字符串最大长度
        for (i,c) in inputStr1.enumerated() {
            if c >= "g" && c <= "z" {
                temp.append(String(c))
                if i != inputStr1.count - 1 { continue }
            }
            if !temp.isEmpty {
                let len = temp.count
                if len <= diffLen && len >= maxLen {
                    if len > maxLen { // 只保留最大长度的有效字符串
                        resDic.removeAll()
                    }
                    maxLen = max(maxLen, len)
                    resDic.updateValue(temp.count, forKey: temp) // 保存有效字符串
                }
                temp = "" // 清空临时字符串，准备拼接下一个有效字符串
            }
        }
        if resDic.count == 0 { // 没有有效字符串就打印Not Found
            print("Not Found")
            return
        }
        for (i,dic) in resDic.enumerated() {
            if i == resDic.count - 1 {
                print(dic.key) // 打印字典序里最后一个有效字符串
            }
        }
        
    }