All pairs shortest paths
------------------------

In this problem, you will implement the Floyd-Warshall algorithm for computing
all-pairs shortest paths in a weighted directed graph.

Input
-----

The input will consist of multiple instances.  The first line of each
instance will contain two integers n and m, representing the number of
nodes and edges in the graph, respectively.  These values will satisfy
1 <= n <= 300 and 0 <= m <= 800.  Following this, there will be
m lines, each containing three integers i, j and w, where 1 <= i <= n and 
1 <= j <= n, indicating that there is an edge from node i to node j. The
weight of this edge is given by w. You can assume that 0 < w < 100.  
The last line for this instance will be a line containing a single integer
x, 1 <= x <= n. 
The end of the input will be indicated by a line with m=n=0.

Output
------

For each input graph, output the cost of the shortest path from node x to 
each of the other nodes, in the format shown below. If there is no path from 
node x to some other node, output "no path" for that node.

Sample Input
------------
5 10
1 2 1
1 4 9
2 4 12
2 5 2
4 3 3
4 5 7
3 5 6
4 2 23
5 1 66
3 4 87
1
3 2
1 2 23
2 1 23
3
0 0

Sample Output
-------------
Graph #1
1: 0
2: 1
3: 12
4: 9
5: 3
Graph #2
1: no path
2: no path
3: 0