#include "bits/stdc++.h"

using namespace std;
typedef long long ll;
const ll MOD = 1e9 + 7;
bool dp[101][10001];
int W[100];
int main() {
	int N;
	cin >> N;
	int sum = 0;
	for (int i = 0; i < N; i++) cin >> W[i], sum += W[i];
	dp[0][0] = 1;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j <= 100 * i; j++) {
			dp[i + 1][j] |= dp[i][j];
			dp[i + 1][j + W[i]] |= dp[i][j];
		}
	}
	if (sum % 2 == 0 && dp[N][sum / 2]) {
		cout << "possible" << endl;
	}
	else {
		cout << "impossible" << endl;
	}
}