Expressways

Byteland has $n$ cities and $m$ roads connecting them. The roads are in poor shape, and because of a lack of funds they have not been repaired for a long time.

The residents are demanding that some of the roads be turned into brand-new expressways. The king agrees to build them, but under one condition: there has to be a construction plan in which every one of the $n$ cities is served by an odd number of expressways. An expressway can only be built on top of a road that already exists.

Deciding which roads become expressways is the same as choosing a subset of the existing roads. For a given road network, decide whether a plan exists in which every city is incident to an odd number of the chosen roads.

The first line contains a single integer $z$ ($1 \le z \le 100$), the number of test sets. The test sets follow.

The first line of a test set contains two integers $n$ and $m$ ($1 \le n \le 100000$, $1 \le m \le 200000$), the number of cities and the number of roads. Each of the next $m$ lines contains two integers $x$ and $y$ ($1 \le x, y \le n$), meaning that cities $x$ and $y$ are joined by a road. The same pair of cities may be joined by more than one road, and a road may connect a city with itself.

The sum of $n$ over all test sets does not exceed $1000000$, and the sum of $m$ does not exceed $2000000$.

For each test set, print a single line.

Print YES if it is possible to choose a subset of the roads so that every city is incident to an odd number of the chosen roads, and print NO otherwise.