#include <bits/stdc++.h>

using namespace std;

#define LOG(...) fprintf(stderr,__VA_ARGS__)
//#define LOG(...)
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort(ALL(c))
#define RSORT(c) sort(RALL(c))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

bool dp[10100+1];

int main() {
    int n;
    cin >> n;
    vi weight(n);
    REP(i, n) cin >> weight[i];

    int sum = accumulate(ALL(weight), 0);
    if (sum % 2 == 0) {
        REP(i, n) {
            int w = weight[i];
            dp[w] = true;
            REP(j, 10001) {
                if (dp[j]) {
                    LOG("%d\n", j+w);
                    dp[j+w] = true;
                }
            }
        }
        if (dp[sum/2] > 0) {
            cout << "possible" << endl;
            return 0;
        }
    }
    cout << "impossible" << endl;
}