The input is read from a text file named countries.in. The first line consists of one integer 1 ≤ n ≤ 1000, the number of cities. The following n lines give the information on the n cities, each city as its own line. Line i + 1 gives the information on city i as the three integers xi, yi, si which are separated by single space characters. All these numbers are in range 0 ≤ xi, yi, si ≤ 1000.