Let ~x_1, x_2, x_3, \dots~ be variables. ~n~ constraints of form ~x_i = x_j~ or ~x_i \ne x_j~ are given. The task asks for whether it is possible to assign values to the variables so that all constraints can be satisfied. For example, if the constraints are ~x_1 = x_2, x_2 = x_3, x_3 = x_4, x_1 \ne x_4~, then those constraints cannot be satisfied simultaneously.

Input Specification

The first line of the input is an integer ~t~ representing the number of instances to solve. The instances are independent. For each instance, the first line is an integer ~n~ representing the number of constraints to be satisfied. In the following ~n~ lines, each line has three integers ~i,j,e~ representing an equality/inequality constraint. If ~e = 1~, the constraint shall be ~x_i = x_j~. If ~e = 0~, the constraint shall be ~x_i \ne x_j~.

Output Specification

The output has ~t~ lines. The ~k~-th line of the output is a string YES or NO. Output YES if the constraints in that instance can be satisfied and NO otherwise.

Sample Input 1

2
2
1 2 1
1 2 0
2
1 2 1
2 1 1

Sample Output 1

NO
YES

Sample Input 2

2
3
1 2 1
2 3 1
3 1 1
4
1 2 1
2 3 1
3 4 1
1 4 0

Sample Output 2

YES
NO

Constraints

Test Case	~n~	~i, j~	Additional Constraints
1	~1 \le n \le 10~	~1 \le i, j \le 10\,000~	~1 \le t \le 10~ ~e \in \{0,1\}~
2
3	~1 \le n \le 100~
4
5	~1 \le n \le 100\,000~
6
7
8	~1 \le n \le 100\,000~	~1 \le i, j \le 1\,000\,000\,000~
9
10