#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pll> P;

const ll INF = 1ll<<30;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int main() {
	int N, M;
	cin >> N >> M;
	
	bool f = false;
	
	REP(i, N) {
		bitset<51> bs(1);
		REP(j, N) if (i != j) bs |= bs << (j + 1);
		if (bs[i + 1]) f = true;
	}
	
	bool ans = M != 0;
	if (f) ans = true;
	
	puts(ans ? "Possible" : "Impossible");
	
	return 0;
}