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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    vector<vector<bool>> dp(n + 1, vector<bool>(200001));
    dp[1][100001] = true;
    for(int i = 1; i < n; i++){
        int v = i + 1;
        for(int j = 0; j <= 200000; j++){
            if(!dp[i][j])continue;
            //dp[i + 1][j] = true;
            if(j + v <= 200000) dp[i + 1][j + v] = true;
            if(j - v >= 0) dp[i + 1][j - v] = true;
            ll v2 = j - 100000;
            if(-100000 <= v2 * v && v2 * v <= 100000) dp[i + 1][v2 * v + 100000] = true;
        }
    }
    cout << (dp[n][m + 100000] ? "Possible" : "Impossible") << '\n';
}