#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define FOR(I,A,B) for(int I = (A); I < (B); ++I) bool dp[51][6000]; int main(){ int n, m; cin >> n >> m; if(n==1){ cout << "Impossible" << endl; return 0; } FOR(i,0,n+1){ FOR(j,0,6000){ dp[i][j] = false; } } dp[0][3000] = true; FOR(i,0,n){ FOR(j,0,6000){ if(!dp[i][j]) continue; dp[i+1][j+(i+1)] = true; dp[i+1][j-(i+1)] = true; } } cout << (dp[n][m+3000] ? "Possible" : "Impossible") << endl; return 0; }