#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
using namespace std;

using ll = long long;
using P = pair<int, int>;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

constexpr int MAX = 10000;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N;
    cin >> N;
    vector<int> W(N);
    for(int i = 0; i < N; ++i)  cin >> W[i];
    int S = accumulate(begin(W), end(W), 0);

    vector<int> dp(MAX + 1), dp2(MAX + 1);
    dp[0] = 1;
    for(int i = 0; i < N; ++i){
        dp2 = dp;
        for(int j = 0; j <= 100 * i; ++j){
            if(!dp[j])  continue;
            dp2[j + W[i]] = 1;
        }
        swap(dp, dp2);
    }

    for(int i = 0; i <= MAX; ++i){
        if(dp[i] && i * 2 == S){
            cout << "possible\n";
            return 0;
        }
    }
    cout << "impossible\n";

    return 0;
}