#include "validation.h"

int main(int argc, char** argv) {
	// Set up the input and answer streams.
	std::ifstream in(argv[1]);
	std::ifstream ans(argv[2]); // Only for custom checker.
	OutputValidator v(argc, argv);

	std::string is_possible;
	ans >> is_possible; // This is either "impossible" or a number, but we don't use `ans` in the
	                    // "possible" case, so that's fine
	std::cerr << is_possible << std::endl;
	if(is_possible == "impossible") {
		v.test_string("impossible", "is_possible");
		v.newline();
	} else {
		int n, m;
		in >> n;
		m                              = n;
		std::vector<std::set<int>> nrs = std::vector<std::set<int>>(n + 1, std::set<int>());
		for(int i = 0; i < m; i++) {
			int u, w, h;
			in >> u >> w >> h;

			int node = v.read_integer("node", 1, n);
			if(node == w) std::swap(u, w);
			if(node == u) {
				v.check(nrs[u].count(1) == 0,
				        "This node already has a street with this housenumber");
				v.check(nrs[w].count(h) == 0,
				        "This node already has a street with this housenumber");
			} else {
				v.check(false, "This street is not connected to this node");
			}
			nrs[u].insert(1);
			nrs[w].insert(h);
			v.newline();
		}
	}
}