acm2003

/**
 * 求绝对值
 */
import java.util.*;
public class acm2003 {


public static void main(String[] args) {
Scanner in=new Scanner(System.in);
while(in.hasNextDouble()){
double a=in.nextDouble();
if(a<0){
a=-a;
System.out.printf("%.2f",a);
System.out.println();
}else{
System.out.printf("%.2f",a);
System.out.println();
}
}
}
}