#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const int INF = 2e9;
const long long INF64 = 3e18;
const long double EPS = 1e-12;
const long double PI = 3.1415926535897932384620;
const long long MD = 925262732;
const long long T = 634521;
const int N = 200100;
const int M = 2010;
const int MAGIC = 4000;
int n, m, d[M][M];
pair<int, int> a[N], b[N];
vector<int> g;
bool check(int dd) {
  for (int i = 0; i < int(m); i++)
    for (int j = 0; j < int(m); j++) d[i][j] = 0;
  for (int i = 0; i < int(n); i++) {
    int first = a[i].first, y1 = a[i].second - dd * 2,
        y2 = a[i].second + dd * 2;
    for (int j = i + 1; j < n; j++) {
      if (a[j].first != first) break;
      if (a[j].second - a[j - 1].second <= dd * 4)
        y2 = a[j].second + dd * 2, i = j;
      else
        break;
    }
    g.clear();
    for (int ii = 0; ii < int(m); ii++) {
      int second = b[ii].first, x1 = b[ii].second - dd * 2,
          x2 = b[ii].second + dd * 2;
      for (int jj = ii + 1; jj < m; jj++) {
        if (b[jj].first != second) break;
        if (b[jj].second - b[jj - 1].second <= dd * 4)
          x2 = b[jj].second + dd * 2, ii = jj;
        else
          break;
      }
      if (second >= y1 && second <= y2 && x1 <= first && x2 >= first)
        g.push_back(ii);
    }
    for (int ii = 0; ii < int(int((g).size())); ii++)
      for (int jj = ii + 1; jj < int((g).size()); jj++) {
        d[g[ii]][g[jj]]++;
        if (d[g[ii]][g[jj]] >= 2) return 1;
      }
  }
  return 0;
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < int(n); i++) {
    int first, second;
    cin >> first >> second;
    a[i].first = first + second;
    a[i].second = second - first;
  }
  sort(a, a + n);
  for (int i = 0; i < int(m); i++) {
    int first, second;
    cin >> first >> second;
    b[i].second = first + second;
    b[i].first = second - first;
  }
  sort(b, b + m);
  int l = 0, r = 3000000;
  while (r - l > 1) {
    int m = (l + r) / 2;
    if (check(m))
      r = m;
    else
      l = m;
  }
  if (check(l))
    cout << l;
  else if (check(r))
    cout << r;
  else
    cout << "Poor Sereja!";
  return 0;
}
