import java.util.*;
class B{
public static void main(String [] args){
Scanner reader=new Scanner(System.in);
double i=1;
while(reader.hasNextDouble()){
i*=reader.nextDouble();
}
System.out.println(i);
}
}
class B{
public static void main(String [] args){
Scanner reader=new Scanner(System.in);
double i=1;
while(reader.hasNextDouble()){
i*=reader.nextDouble();
}
System.out.println(i);
}
}