#include #include #include #include #include #include #define rep(i, n) for(i = 0; i < (n); i++) #define chmax(x, y) x = max(x, y) #define chmin(x, y) x = min(x, y) #define MOD 1000000007 #define PI 3.14159265358979323846 #define INF 1 << 30 using namespace std; typedef long long ll; typedef pair pp; int main(void) { int num, i, j, sum = 0, a; cin >> num; vector dp(100 * num + 1, 0); dp[0] = true; rep(i, num) { cin >> a; sum += a; rep(j, dp.size()) { if (dp[j]) dp[j + a] = true; } } if ((sum & 1) || !dp[sum >> 1]) printf("impossible\n"); else printf("possible\n"); return 0; }