#include <bits/stdc++.h>
using namespace std;

int main(){
    int N, M = 10010, S = 0;
    cin >> N;

    vector<bool> dp(M, false);
    dp[0] = true;
    for (int i = 0; i < N; i++){
        int w;
        cin >> w;
        S += w;
        for (int j = M-1; j >= w; j--){
            if (dp[j-w]) dp[j] = true;
        }
    }

    if (S%2 != 0 || !dp[S/2]) cout << "im";
    cout << "possible" << endl;
}