#include #include #include #include #include #include #include #include #include #include #include using namespace std; using namespace atcoder; typedef long long ll; #define rep(i,n) for (int i = 0; i < int(n);i++) int main(){ int n; cin >> n; vector> dp(n+1,vector (1001)); int sum = 0; vector a(n); rep(i,n){ cin >> a[i]; sum += a[i]; } dp[0][0] = true; for (int i = 0; i < n;i++){ for (int j = 0; j < 1000;j++){ if (dp[i][j]){ dp[i+1][j] = true; dp[i+1][j+a[i]] = true; } } } bool yes = false; for (int w = 0; w <= 1000;w++){ if (dp[n][w] && w*2 == sum){ yes = true; break; } } if (yes) cout << "possible" << endl; else cout << "impossible" << endl; return 0; }