C++ :

#include<bits/stdc++.h>
using namespace std;
int main(){
	double n;
	cin>>n;
	cout<<fixed<<setprecision(2)<<abs(n)<<endl;
	return 0;
}

Java :

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		double a = sc.nextDouble();
		if(a > 0){
			System.out.println(String.format("%.2f", a));
		}else{
			a = -1 * a;
			System.out.println(String.format("%.2f", a));
		}
	}

}

Python :

a=float(input())
b=abs(a)
print("%.2f"%b)