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

int main(void){
//input
	int H,S; cin >> H >> S;
//calc
	bool isPoss;
	if(abs(H - S) % 2 == 0){
		isPoss = true;
	}else{
		isPoss = false;
	}
//output
	if(isPoss){
		cout << "Possible" << endl;
	}else{
		cout << "Impossible" << endl;
	}
}