All of us are familiar with the reign of the great mughal ruler , Akbar. He was always concerned with the prosperity and safety of the people . Therefore to safeguard his kingdom (which consisted of N cities) he wanted to place secret soldiers all over his kingdom so as to protect the people . But since his kingdom is very large therefore he wanted to place them in such a way that every city is protected by one and only one soldier.According to Akbar , this is the optimum placement.

 As for these soldiers they can protect multiple cities according to their strengths.

The strength of a particular soldier is defined as the maximum distance upto which a guard can protect a city from its base city(base city is the city assigned to the guard). If there are 3 cities C1, C2 and C3 such that C1 C2 and C2 C3 are connected respectively, if a soldier with strength 1 is placed at C2 then all the cities C1, C2 and C3 are protected by that soldier.

Also the kingdom is connected with a network of secret two way roads for faster access only accessible to these soldiers. The length of any road on this network between any two cities is 1 kms .There are R such roads in the kingdom. 

He had given this task to birbal to place the soldiers . Birbal didn't wanted to be a fool in front of the king , therefore took the job and placed M soldiers all over the kingdom but he was not very good at mathematics . But since he is very intelligent he somehow places the guards all over the kingdom and now turns to you (who is a genius mathematician ;) ) to check whether his placements are good or not.

Your task is to check if the placements of the soldiers are optimum or not.

INPUT

The input consists of T test cases . Each test case then consists of 3 parts.The first line consists of N, R and M.

the next R lines consists of two numbers A and B denoting the two cities between which a road exists .

the next M lines consists of 2 numbers, city number K and strength S of that particular soldier.

=> strength 0 means it will only guard the city on which it is present .

=> assume every city is accesible from every other city .

CONSTRAINTS

T <= 10;

1 <= N <= 10^6;

N -1 <= R <= min( 10^7 , ( N * (N - 1) ) / 2) );

1 <= K <= N;

0 <= S <= 10^6

OUTPUT

print "Yes" if the soldiers are placed optimumly else print "No". (quotes are for clarity)

SAMPLE INPUT

2

3 2 2

1 2

2 3

1 2

2 0

4 5 2

1 4

1 2

1 3

4 2

3 4

2 1

3 0

SAMPLE OUTPUT

No

Yes

WARNING ==> Large input.