#include <bits/stdc++.h>
using namespace std;

int main()
{
  string h, s;
  cin >> h >> s;
  int v1 = h.back() - '0', v2 = s.back() - '0';
  cout << ((v1 - v2) % 2 == 0 ? "Possible" : "Impossible") << endl;
}