/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		int n; //Количество вводимых чисел.
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		double a,f; //а-переменна для считывания чисел, f-произведения введенных чисел, m-результат из f умноженый на -1 в степени n+1.
		f=-1;
		for(int k=1; k<=n; ++k){
			a = sc.nextDouble();
			f *= -a;
			System.out.print(f);
			if(k<n) 
				System.out.print(", ");
			else
				System.out.print(".");
 
		}
	}
}

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NwoxLjgKMy45CjAuMDAwMQotNzkKNDU2Ljk4CjAuOTAwMQo0

7
1.8
3.9
0.0001
-79
456.98
0.9001
4