#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("possible");}else{puts("impossible");}
#define MAX_N 200005

int main() {
    int n;
    cin >> n;
    int w[n];
    int sum = 0;
    rep(i,n){
        cin >> w[i];
        sum += w[i];
    }

    int dp[20000] = {};
    dp[0] = 1;
    rep(i,n){
        drep(j,20000){
            if(dp[j] == 1){
                dp[j + w[i]] = 1;
            }
        }
    }

    if(sum % 2 == 0 && dp[sum/2] == 1)yn;

    return 0;
}