Codeforces Beta Round 55 (Div. 2)
E
Shortest Path
Codeforces
2000
原题
← D→
翻译中…

In Ancient Berland there were $*n*$ cities and $*m*$ two-way roads of equal length. The cities are numbered with integers from $1$ to $*n*$ inclusively. According to an ancient superstition, if a traveller visits three cities $*a*_{*i*}$, $*b*_{*i*}$, $*c*_{*i*}$ in row, without visiting other cities between them, a great disaster awaits him. Overall there are $*k*$ such city triplets. Each triplet is ordered, which means that, for example, you are allowed to visit the cities in the following order: $*a*_{*i*}$, $*c*_{*i*}$, $*b*_{*i*}$. Vasya wants to get from the city $1$ to the city $*n*$ and not fulfil the superstition. Find out which minimal number of roads he should take. Also you are required to find one of his possible path routes.

翻译中…

Input

翻译中…

The first line contains three integers $*n*$, $*m*$, $*k*$ ($2 ≤ *n* ≤ 3000, 1 ≤ *m* ≤ 20000, 0 ≤ *k* ≤ 10^{5}$) which are the number of cities, the number of roads and the number of the forbidden triplets correspondingly.

翻译中…

Then follow $*m*$ lines each containing two integers $*x*_{*i*}$, $*y*_{*i*}$ ($1 ≤ *x*_{*i*}, *y*_{*i*} ≤ *n*$) which are the road descriptions. The road is described by the numbers of the cities it joins. No road joins a city with itself, there cannot be more than one road between a pair of cities.

翻译中…

Then follow $*k*$ lines each containing three integers $*a*_{*i*}$, $*b*_{*i*}$, $*c*_{*i*}$ ($1 ≤ *a*_{*i*}, *b*_{*i*}, *c*_{*i*} ≤ *n*$) which are the forbidden triplets. Each ordered triplet is listed mo more than one time. All three cities in each triplet are distinct.

翻译中…

City $*n*$ can be unreachable from city $1$ by roads.

翻译中…

Output

翻译中…

If there are no path from $1$ to $*n*$ print -1. Otherwise on the first line print the number of roads $*d*$ along the shortest path from the city $1$ to the city $*n*$. On the second line print $*d* + 1$ numbers — any of the possible shortest paths for Vasya. The path should start in the city $1$ and end in the city $*n*$.

翻译中…

样例

Input #1
4 4 1
1 2
2 3
3 4
1 3
1 4 3
Output #1
2
1 3 4
InputCopy OutputCopy
Input #2
3 1 0
1 2
Output #2
-1
InputCopy OutputCopy
Input #3
4 4 2
1 2
2 3
3 4
1 3
1 2 3
1 3 4
Output #3
4
1 3 2 3 4
InputCopy OutputCopy
题目信息
题号
59E
时间限制
3 s
内存限制
256 MB
标签
图论
最短路

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。