#include <iostream> #include <algorithm> #include <vector> #include <map> #include <string> #include <numeric> #include <cstring> #include <cmath> #include <set> #include <queue> #include <stack> const int MOD = 1e9 + 7; const int iINF = 1000000000; const long long int llINF = 1000000000000000000; #define rep(i, n) for (int i = 0; i < (n); i++) using namespace std; using ll = long long int; using P = pair<int, int>; using edge = struct { int to; int cost; }; int dx[4] = {1, 0, -1, 0}; int dy[4] = {0, 1, 0, -1}; bool dp[10010]; int main() { int N; cin >> N; vector<int> W(N); rep(i, N) cin >> W[i]; int sum = accumulate(W.begin(), W.end(), 0); dp[0] = true; rep(i, N) { for (int j = 0; j <= sum; j++) { if(j + W[i] > sum) continue; dp[j + W[i]] = dp[j]; } } cout << (dp[sum / 2] && sum % 2 == 0 ? "possible" : "impossible") << endl; return 0; }