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

#define rep(i, n) for( ll i = 0; i < n; i++ )
using ll = long long;

int main() {
	ll h, s;
	cin >> h >> s;
	string ans = "Possible";
	if(abs(h - s) % 2) ans = "Impossible";
	cout << ans << endl;
}