N = int(input()) weights_list = [0] + list(map(int, input().split(' '))) total = sum(weights_list) if total % 2 == 1: print("impossible") exit() #dp = np.zeros((N + 1, 10001), dtype=np.bool) dp = [0 for _ in range(10001)] dp[0] = True for i in range(1, N + 1): for j in range(10000, -1, -1): if (dp[j] == True) or ((j >= weights_list[i]) and (dp[j-weights_list[i]] == True)): dp[j] = True if dp[total // 2]: print("possible") else: print("impossible")