#include <assert.h>
#include <ctype.h>
#include <float.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>

#include <algorithm>
#include <bitset>
#include <complex>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
using namespace std;

#define SZ(a) (int)(a).size()
#define FOR(i,a,b) for (int i=(a); i<=(b); ++i)
#define REP(i,n) for (int i=0; i<(n); ++i)
#define ALL(c) c.begin(), c.end()
#define CLR(c,n) memset(c, n, sizeof(c))
#define MCPY(d, s) memcpy(d, s, sizeof(d))
#define TR(it, c) for (auto it = c.begin();it != c.end(); ++it)
#define CONTAIN(it, c) (c.find(it) != c.end())
typedef vector<int> VI;
typedef pair<int, int> PII;
template <class T> void checkmin(T &a, T b) { if (b<a) a=b; }
template <class T> void checkmax(T &a, T b) { if (b>a) a=b; }
typedef long long LL;
const int INF=0x3F3F3F3F;

int n, w[100];
bitset<5<<10> mark;;

bool go() {
  int s = accumulate(w, w+n, 0);
  if (s % 2) return false;
  s /= 2;
  mark.reset();
  mark.set(0);
  REP(k, n) {
    int d = w[k];
    for (int i = s, j = s-d; j >= 0; --i, --j) {
      if (mark[j]) mark.set(i);
    }
  }
  return mark[s];
}
int main(int argc, char *argv[]) {
  while (scanf("%d", &n) == 1) {
    REP(i, n) scanf("%d", &w[i]);
    printf("%spossible\n", go() ? "" : "im");
  }
}