n = int(input()) w = list(map(int, input().split())) w_sum = 0 for i in w: w_sum += i if w_sum % 2 == 1: print("impossible") elif w_sum % 2 == 0: dp = [False for _ in range(w_sum // 2 + 1)] dp[0] = True for i in range(n): for j in range(w_sum // 2 + 1): if dp[j] and j + w[i] <= w_sum // 2: dp[j + w[i]] = True if dp[-1]: print("possible") else: print("impossible")