there n city Cyberland number 1 n connect m bidirectional road the jth road connect city aj bjFor tourist souvenir sell city Cyberland in particular city sell price winow q query handle there type query C w the price city change w a b now tourist travel city b he choose route do not want visit city twice he buy souvenir city souvenir cheap possibly exactly city b you output minimum possible price buy souvenir travelmore formally define route follow a route sequence city x1x2xk k certain positive integer for 1ijkxixj for 1ik road connect xi xi1 the minimum price route minwx1wx2wxk the require answer minimum value minimum price valid route b