#include <bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)

using namespace std;

int a = 0, t = 0, tw, dp[110][10100], dp2[110][10100], n,w[110];

int dfs(int d, int sum){

	///test///
	//printf("d : %3d  sum : %3d\n",d,sum);
	
	if(dp[d][sum]!=-1) return dp[d][sum];

	if(d == n-1){
		return dp[d][sum] = (sum == tw);
	}	

	return dp[d][sum] = (dfs(d+1, sum) || dfs(d+1,sum + w[d+1]));

}

//for first f =1, avoid repetition of dp[][].
int dfs2(int d, int sum){
	
	if(dp2[d][sum]!=-1) return dp2[d][sum];

	if(d == n-1){
		return dp2[d][sum] = (sum == tw);
	}	

	return dp2[d][sum] = (dfs2(d+1, sum) || dfs2(d+1, sum + w[d+1]));

}

int main(){
	cin>>n;

	for(int i=0; i<n; i++){
		cin>>w[i];
		t += w[i];
	}

	tw = t/2;

	for(int i=0; i<n; i++){
		for(int j=0; j<10002; j++){	
			dp[i][j] = -1; 
			dp2[i][j] = -1;
		}
	}

	dfs(0,0);
	dfs2(0,w[0]);

	/*rep(i,0,n){
		for(int j=0; j<10001; j += 100){
			printf("%2d",dp[i][j]);
		}
		cout<<endl;
	}
*/
	if((t%2==0) && (dp[0][0] || dp2[0][w[0]])){
		cout<<"possible"<<endl;
	}else{
		cout<<"impossible"<<endl;
	}

	return 0;
}