20 2 s 65 MB

While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way path that delivers you to its destination at a time that is BEFORE you entered the wormhole! Each of FJ's farms comprises *N* (1 ≤ *N* ≤ 500) fields conveniently numbered 1..*N*, *M* (1 ≤ *M* ≤ 2500) paths, and *W* (1 ≤ *W* ≤ 200) wormholes.

As FJ is an avid time-traveling fan, he wants to do the following: start at some field, travel through some paths and wormholes, and return to the starting field a time before his initial departure. Perhaps he will be able to meet himself :) .

To help FJ find out whether this is possible or not, he will supply you with complete maps to *F* (1 ≤ *F* ≤ 5) of his farms. No paths will take longer than 10,000 seconds to travel and no wormhole can bring FJ back in time by more than 10,000 seconds.

Line 1: A single integer, *F*. *F* farm descriptions follow.

Line 1 of each farm: Three space-separated integers respectively:*N*, *M*, and *W*

Lines 2..*M*+1 of each farm: Three space-separated numbers (*S*, *E*, *T*) that describe, respectively: a bidirectional path between *S* and *E* that requires *T* seconds to traverse. Two fields might be connected by more than one path.

Lines*M*+2..*M*+*W*+1 of each farm: Three space-separated numbers (*S*, *E*, *T*) that describe, respectively: A one way path from *S* to *E* that also moves the traveler back *T* seconds.

Line 1 of each farm: Three space-separated integers respectively:

Lines 2..

Lines

Lines 1..*F*: For each farm, output "YES" if FJ can achieve his goal, otherwise output "NO" (do not include the quotes).

## Sample Input | ## Sample Output |
---|---|

2 3 3 1 1 2 2 1 3 4 2 3 1 3 1 3 3 2 1 1 2 3 2 3 4 3 1 8 | NO YES |