#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for (int (i)=(a);(i)<(b);(i)++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(), (v).end()

typedef vector<int> VI;
typedef long long LL;

const int MAXN = (int) 1e5 + 10;

int solve(int a, int b, int c, int d) {
  VI v({a, b, c, d});
  sort(v.begin(), v.end());
  do {
    if (v[0] * v[3] == v[1] * v[2]) {
      return true;
    } 
  } while (next_permutation(ALL(v)));
  return false;
}

int solveAnother(int a, int b, int c, int d) {
  VI v({a, b, c, d});
  sort(v.begin(), v.end());
  return v[0] * v[3] == v[1] * v[2];
}

int main() {
  int a, b, c, d, ok = false;
  scanf("%d %d %d %d", &a, &b, &c, &d);
  puts(solve(a, b, c, d) ? "Possible" : "Impossible"); 
  return 0;
}