PROGRAMMING:Xiaoyu dominates the world
Recently, Xiaoyu's determination to dominate the world has become stronger and stronger,
However, although Xiaoyu is brave, he has no strategy. Therefore, Xiaoyu now asks you
Now there are $$n$$countries. There are $$k$$roads. Now, because the information of Xiao Yu is not awesome, only the $$m$$road in the $$k$$road has been found.
Now there is a concept of minimum battle damage allocation. It is defined as: give a graph $$g $$, and a subset of the edges of graph $$g $$$$$s $$, if the edges in $$s $$can cover all the points in graph $$g $$, and $$s $$is the one with the least number of edges in the edge set satisfying the condition, $$s $$is called the minimum battle damage allocation of graph $$g $$
Now, Xiaoyu wants to ask you whether this $$M $$road can be the minimum war damage distribution of these $$n $$countries
###Input format:
The first line gives a positive integer, $$t $$, indicating that there is an example of the $$t $$group. $$1 $$< = $$t $$< = $$10 $$
In the second line, two positive integers $$n $$and $$M $$indicate that there are $$n $$countries and $$M $$roads that have been found
Next, there are two positive integers in the $$M $$line, $$a $, $$B $$for a road
$$1$$<=$$n$$<=$$200000$$,$$1$$<=$$m$$<=$$300000$$.
$$1$$<=$$a$$,$$b$$<=$$n$$
###Output format:
If this $$M $$road is likely to be the minimum war damage allocation of these countries, then output $$yes $$, otherwise output $$no $$
$$tips $$: answers are case sensitive
###Input example:
Here is a set of inputs. For example:
```in
two
4 2
1 2
3 4
4 3
1 2
2 3
3 4
```
###Output example:
The corresponding output is given here. For example:
```out
Yes
No
```
answer：If there is no answer, please comment
However, although Xiaoyu is brave, he has no strategy. Therefore, Xiaoyu now asks you
Now there are $$n$$countries. There are $$k$$roads. Now, because the information of Xiao Yu is not awesome, only the $$m$$road in the $$k$$road has been found.
Now there is a concept of minimum battle damage allocation. It is defined as: give a graph $$g $$, and a subset of the edges of graph $$g $$$$$s $$, if the edges in $$s $$can cover all the points in graph $$g $$, and $$s $$is the one with the least number of edges in the edge set satisfying the condition, $$s $$is called the minimum battle damage allocation of graph $$g $$
Now, Xiaoyu wants to ask you whether this $$M $$road can be the minimum war damage distribution of these $$n $$countries
###Input format:
The first line gives a positive integer, $$t $$, indicating that there is an example of the $$t $$group. $$1 $$< = $$t $$< = $$10 $$
In the second line, two positive integers $$n $$and $$M $$indicate that there are $$n $$countries and $$M $$roads that have been found
Next, there are two positive integers in the $$M $$line, $$a $, $$B $$for a road
$$1$$<=$$n$$<=$$200000$$,$$1$$<=$$m$$<=$$300000$$.
$$1$$<=$$a$$,$$b$$<=$$n$$
###Output format:
If this $$M $$road is likely to be the minimum war damage allocation of these countries, then output $$yes $$, otherwise output $$no $$
$$tips $$: answers are case sensitive
###Input example:
Here is a set of inputs. For example:
```in
two
4 2
1 2
3 4
4 3
1 2
2 3
3 4
```
###Output example:
The corresponding output is given here. For example:
```out
Yes
No
```
answer：If there is no answer, please comment