description: Vupsen and Pupsen were gifted an integer array. Since Vupsen doesn't like the number 0, he threw away all numbers equal to 0 from the array. As a result, he got an array a of length n.
  
  Pupsen, on the contrary, likes the number 0 and he got upset when he saw the array without zeroes. To cheer Pupsen up, Vupsen decided to come up with another array b of length n such that ∑_{i=1}^{n}a_i ⋅ b_i=0. Since Vupsen doesn't like number 0, the array b must not contain numbers equal to 0. Also, the numbers in that array must not be huge, so the sum of their absolute values cannot exceed 10^9. Please help Vupsen to find any such array b!
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 100) — the number of test cases. The next 2 ⋅ t lines contain the description of test cases. The description of each test case consists of two lines.
  
  The first line of each test case contains a single integer n (2 ≤ n ≤ 10^5) — the length of the array.
  
  The second line contains n integers a_1, a_2, …, a_n (-10^4 ≤ a_i ≤ 10^4, a_i ≠ 0) — the elements of the array a.
  
  It is guaranteed that the sum of n over all test cases does not exceed 2 ⋅ 10^5.
  
  Output
  
  For each test case print n integers b_1, b_2, …, b_n — elements of the array b (|b_1|+|b_2|+… +|b_n| ≤ 10^9, b_i ≠ 0, ∑_{i=1}^{n}a_i ⋅ b_i=0).
  
  It can be shown that the answer always exists.
  
  Example
  
  Input
  
  
  3
  2
  5 5
  5
  5 -2 10 -9 4
  7
  1 2 3 4 5 6 7
  
  
  Output
  
  
  1 -1
  -1 5 1 -1 -1
  -10 2 2 -3 5 -1 -1
  
  Note
  
  In the first test case, 5 ⋅ 1 + 5 ⋅ (-1)=5-5=0. You could also print 3 -3, for example, since 5 ⋅ 3 + 5 ⋅ (-3)=15-15=0
  
  In the second test case, 5 ⋅ (-1) + (-2) ⋅ 5 + 10 ⋅ 1 + (-9) ⋅ (-1) + 4 ⋅ (-1)=-5-10+10+9-4=0.
solution: import java.io.*;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.Deque;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.PriorityQueue;
  import java.util.Queue;
  import java.util.Scanner;
  import java.util.Stack;
  import java.util.TreeMap;
  import java.util.TreeSet;
  
  public class Main {
  	int t,a,b,c,i,j,n,k,u,v,w,x,l,r,ans,pre,gcd;
  	int[]p=new int[100005];
  	int gcd(int a,int b) {
  		if(b==0)return a;
  		return gcd(b,a%b);
  	}
  	boolean book;
  	void o() {
  		if(book)out.print(" ");
  		else book=true;
  	}
  	void run(String[]args) throws IOException{
  //		Scanner in=new Scanner(System.in);
  		t=in();
  		while(t-->0)
  		{
  			n=in();
  			pre=0;
  			i=0;
  			book=false;
  			if(n%2==1) {
  				a=in();
  				b=in();
  				c=in();
  				i+=3;
  				if(Math.abs(a)==Math.abs(b)&&Math.abs(b)==Math.abs(c)) {
  					o();
  					if(a>0)out.print(1);
  					else out.print(-1);
  					o();
  					if(b>0)out.print(1);
  					else out.print(-1);
  					o();
  					if(c>0)out.print(-2);
  					else out.print(2);
  				}else if(Math.abs(a)!=Math.abs(b)) {
  					p[0]=1;
  					if(a*b>0) {
  						p[1]=-1;
  						pre=a-b;
  					}else {
  						p[1]=1;
  						pre=a+b;
  					}
  					if(pre*c>0) {
  						p[2]=-1;
  					}else {
  						p[2]=1;
  					}
  					pre=Math.abs(pre);
  					c=Math.abs(c);
  					gcd=gcd(pre,c);
  					pre/=gcd;
  					c/=gcd;
  					o();
  					out.print(p[0]*c);
  					o();
  					out.print(p[1]*c);
  					o();
  					out.print(p[2]*pre);
  				}else if(Math.abs(b)!=Math.abs(c)) {
  					p[1]=1;
  					if(b*c>0) {
  						p[2]=-1;
  						pre=b-c;
  					}else {
  						p[2]=1;
  						pre=b+c;
  					}
  					if(pre*a>0) {
  						p[0]=-1;
  					}else {
  						p[0]=1;
  					}
  					pre=Math.abs(pre);
  					a=Math.abs(a);
  					gcd=gcd(pre,a);
  					pre/=gcd;
  					a/=gcd;
  					o();
  					out.print(p[0]*pre);
  					o();
  					out.print(p[1]*a);
  					o();
  					out.print(p[2]*a);
  				}else if(Math.abs(a)!=Math.abs(c)) {
  					p[0]=1;
  					if(c*b>0) {
  						p[2]=-1;
  						pre=a-c;
  					}else {
  						p[2]=1;
  						pre=a+c;
  					}
  					if(pre*b>0) {
  						p[1]=-1;
  					}else {
  						p[1]=1;
  					}
  					pre=Math.abs(pre);
  					b=Math.abs(b);
  					gcd=gcd(pre,b);
  					pre/=gcd;
  					b/=gcd;
  					o();
  					out.print(p[0]*b);
  					o();
  					out.print(p[1]*pre);
  					o();
  					out.print(p[2]*b);
  				}
  			}
  			for(;i<n;i+=2)
  			{
  				a=in();
  				b=in();
  				p[i]=1;
  				if(a*b>0) {
  					p[i+1]=-1;
  				}else {
  					p[i+1]=1;
  				}
  				a=Math.abs(a);
  				b=Math.abs(b);
  				gcd=gcd(a,b);
  				a/=gcd;
  				b/=gcd;
  				o();
  				out.print(b*p[i]);
  				o();
  				out.print(a*p[i+1]);
  			}
  			out.println();
  		}
  		out.flush();
  	}
  	public static void main(String[]args) throws IOException {
  		new Main().run(args);
  	}
  	StreamTokenizer in=new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
  	PrintWriter out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
  	double ind() throws IOException {
  		in.nextToken();
  		return in.nval;
  	}
  	int in() throws IOException {
  		in.nextToken();
  		return(int)in.nval;
  	}
  	long inl() throws IOException {
  		in.nextToken();
  		return(long)in.nval;
  	}
  	String ins()throws IOException{
  		in.nextToken();
  		return in.sval;
  	}
  	class graph{
  		int[]to,nxt,head;
  		int cnt;
  		void init(int n) {
  			cnt=1;
  			for(int i=1;i<=n;i++)
  			{
  				head[i]=0;
  			}
  		}
  		public graph(int n) {
  			to=new int[n<<1];
  			nxt=new int[n<<1];
  			head=new int[n];
  			cnt=1;
  		}
  		void add(int u,int v) {
  			to[cnt]=v;
  			nxt[cnt]=head[u];
  			head[u]=cnt++;
  		}
  	}
  }
  