/* Topcoder SRM 699, D2, 500-pointer: SegmentsAndPoints.
   James S. Plank
   October 9, 2016 */

#include <string>
#include <vector>
#include <list>
#include <cmath>
#include <algorithm>
#include <map>
#include <set>
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

class SegmentsAndPoints
{
    public:
        string isPossible(vector <int> p, vector <int> l, vector <int> r);
};

string SegmentsAndPoints::isPossible(vector <int> p, vector <int> l, vector <int> r)
{
    int i, j, best_segment;
    vector <int> done;

    /* Start by sorting p, and setting all of the "done" entries to zero. */

    sort(p.begin(), p.end());
    done.resize(p.size(), 0);

    /* Now, for each point in p, find the segment that is not done, contains
       the point, and has the smallest r value.  Put that into "best_segment" */

    for (i = 0; i < p.size(); i++) {
        best_segment = -1;
        for (j = 0; j < p.size(); j++) {
            if (!done[j] && l[j] <= p[i] && r[j] >= p[i]) {
                if (best_segment == -1 || r[j] < r[best_segment]) best_segment = j;
            }
        }

        /* If there is such segment, return "Impossible.  Otherwise,
           set the segment's "done" value to 1. */

        if (best_segment == -1) return "Impossible";
        done[best_segment] = 1;
    }

    /* If we've reached the end, return "Possible" */

    return "Possible";
}