#include #define int long long #define REP(i, b) for(int i = 0; i < (b); i++) #define REPS(i, b) for(int i = 1; i <= (b); i++) #define ALL(v) (v).begin(), (v).end() using namespace std; using pi = pair; using vi = vector; using vs = vector; using vb = vector; using vpi = vector; using vvi = vector; using vvb = vector; const int INF = 1e10; const int MOD = 1e9+7; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; } signed main() { cin.tie(nullptr); ios_base::sync_with_stdio(false); cout << fixed << setprecision(10); int N; cin >> N; vi W(N); REP(i, N) cin >> W[i]; REP(b, 1 << N) { int x = 0, y = 0; REP(i, N) { if(b & (1 << i)) x += W[i]; else y += W[i]; } if(x == y) { cout << "possible" << endl; return 0; } } cout << "impossible" << endl; }