1227. Rally Championship
Time limit: 1.0 second
Memory limit: 64 MB
A high-level international rally championship is about to be held. The rules of the race state that the race is held on ordinary roads and the route has a fixed length. You are given a map of the cities and two-way roads connecting it. To make the race safer it is held on one-way roads. The race may start and finish anyplace on the road. Determine if it is possible to make a route having a given length S.
Input
The first line of the input contains the number of cities M, the number of roads N and the length S of the route. 1 ≤ M ≤ 100; 1 ≤ N ≤ 10000; 1 ≤ S ≤ 106. S is integer.
The following N lines describe the roads as triples of integers: P, Q, R. Here P and Q are cities connected with a road, and R is the length of this road. All numbers satisfy the following restrictions: 1 ≤ P, Q ≤ M; 1 ≤ R ≤ 32000.
Output
Write YES to the output if it is possible to make a required route and NO otherwise. Note that answer must be written in capital Latin letters.