A problem with metis

I want to use METIS to reorder a sparse matrix but come to a problem that I can't solve it.It produces errors in reading the graph input file when the graph has weights associated with both the edges & vertices despite the graph having exactly the right number of edges, METIS complains of an error. Here is a sample :
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*** I detected an error in your input file ***
In the first line of the file, you specified that the graph contained
11 edges. However, I only found 14 edges in the file.
Please specify the correct number of edges in the first line of the file.
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This is the content of the graph file:
7 11 11
4 5 1 3 2 2 1
2 1 1 3 2 4 1
5 5 3 4 2 2 2 1 2
3 2 1 3 2 6 2 7 5
1 1 1 3 3 6 2
6 5 2 4 2 7 6
2 6 6 4 5
This is really strange, because the graph has exactly 11 edges (as METIS itself reports), but the
program still produces an error.When I exchange the number of the edges to 14,it will come to :
-------------------------------------------------------------
*** I detected an error in your input file ***
In the first line of the file, you specified that the graph contained
14 edges. However, I only found 14 edges in the file.
Please specify the correct number of edges in the first line of the file.
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Thank you very much for your help!