import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Run run = new Run(scanner);
    }
}

interface General {
    default void sp(Object... o) {
        int i;
        final int end = o.length - 1;
        for (i = 0; i < end; i++)
            System.out.print(o[i] + " ");
        System.out.println(o[i]);
    }
}

class Run implements General {
    Run(Scanner scanner) {
        System.out.printf("%.2f", scanner.nextBigDecimal().abs());
    }
}