Solution in JavaScript/TypeScript

In JavaScript/TypeScript, the situation is a bit different. The parseInt function does not throw an exception when the conversion fails. Instead, it returns NaN (Not-a-Number), which means we need additional validation to handle this case. Due to the challenge's restrictions, which do not allow the use of conditionals, it was not possible to submit a solution that met all the requirements. Here is an attempt at a solution in TypeScript using parseInt for conversion, but it requires additional validation for NaN:

function throwBadString(): never {
    throw new Error("Bad String");
}   

function main() {
    const S: string = readLine();
    
    try {
        const num = parseInt(S);
        isNaN(num) && throwBadString();
        console.log(num);
    } catch (error) {
        console.log("Bad String");
    }
}

Solution in Java

In Java, the solution was straightforward thanks to Integer.parseInt, which throws a NumberFormatException if the string cannot be converted to an integer. This allows us to handle the conversion error clearly and simply using a try-catch block. Here's the code:

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

        String S = bufferedReader.readLine();
        
        try {
            int result = Integer.parseInt(S);
            System.out.println(result);
        } catch (NumberFormatException e) {
            System.out.println("Bad String");
        }

        bufferedReader.close();
    }
}