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Language: I Wanna Go Home
Description The country is facing a terrible civil war----cities in the country are divided into two parts supporting different leaders. As a merchant, Mr. M does not pay attention to politics but he actually knows the severe situation, and your task is to help him reach home as soon as possible. "For the sake of safety,", said Mr.M, "your route should contain at most 1 road which connects two cities of different camp." Would you please tell Mr. M at least how long will it take to reach his sweet home? Input The input contains multiple test cases. The first line of each case is an integer The second line contains one integer The following Next part contains To simplify the problem, we assume that Mr. M starts from city 1 and his target is city 2. City 1 always supports leader 1 while city 2 is at the same side of leader 2. Note that all roads are bidirectional and there is at most 1 road between two cities. Input is ended with a case of Output For each test case, output one integer representing the minimum time to reach home. If it is impossible to reach home according to Mr. M's demands, output -1 instead. Sample Input 2 1 1 2 100 1 2 3 3 1 2 100 1 3 40 2 3 50 1 2 1 5 5 3 1 200 5 3 150 2 5 160 4 3 170 4 2 170 1 2 2 2 1 0 Sample Output 100 90 540 Source |

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