#include <bits/stdc++.h>
using namespace std;
template <typename T, typename U>
inline void smin(T &a, U b) {
  if (a > b) a = b;
}
template <typename T, typename U>
inline void smax(T &a, U b) {
  if (a < b) a = b;
}
inline void gn(int &first) {
  char c, sg = 0;
  while (c = getchar(), (c > '9' || c < '0') && c != '-')
    ;
  for ((c == '-' ? sg = 1, c = getchar() : 0), first = 0; c >= '0' && c <= '9';
       c = getchar())
    first = (first << 1) + (first << 3) + c - '0';
  if (sg) first = -first;
}
inline void print(int first) {
  if (first < 0) {
    putchar('-');
    return print(-first);
  }
  if (first < 10) {
    putchar('0' + first);
    return;
  }
  print(first / 10);
  putchar(first % 10 + '0');
}
int power(int a, int b, int m, int ans = 1) {
  for (; b; b >>= 1, a = 1LL * a * a % m)
    if (b & 1) ans = 1LL * ans * a % m;
  return ans;
}
int first[2010], second[2010], xx[2010], yy[2010];
pair<int, int> p[2010];
int n, m, flag, vst[2010][2010], tmp[2010];
int can(int mid) {
  int L = mid << 1;
  ++flag;
  for (int i = 0, j; i < n; i = j) {
    for (j = i + 1; j < n; j++) {
      if (second[i] != second[j]) break;
      if (first[j] - first[j - 1] > L * 2) break;
    }
    int st = first[i] - L, ed = first[j - 1] + L, cnt = 0;
    for (int k = 0, kk; k < m; k = kk) {
      for (kk = k + 1; kk < m; kk++) {
        if (xx[k] != xx[kk]) break;
        if (yy[kk] - yy[kk - 1] > L * 2) break;
      }
      if (xx[k] < st || xx[k] > ed) continue;
      if (yy[k] - L > second[i] || yy[kk - 1] + L < second[i]) continue;
      for (int j = 0; j < cnt; j++) {
        if (vst[tmp[j]][k] == flag) return true;
        vst[tmp[j]][k] = flag;
      }
      tmp[cnt++] = k;
    }
  }
  return false;
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < n; i++) {
    int u, v;
    gn(u);
    gn(v);
    p[i] = pair<int, int>(u + v, u - v);
  }
  sort(p, p + n);
  for (int i = 0; i < n; i++) first[i] = p[i].second, second[i] = p[i].first;
  for (int i = 0; i < m; i++) {
    int u, v;
    gn(u);
    gn(v);
    p[i] = pair<int, int>(u - v, u + v);
  }
  sort(p, p + m);
  for (int i = 0; i < m; i++) xx[i] = p[i].first, yy[i] = p[i].second;
  int st = 0, ed = (int)2e8 + 1;
  while (ed - st > 1) {
    int mid = st + ed >> 1;
    if (can(mid))
      ed = mid;
    else
      st = mid;
  }
  if (ed == (int)2e8 + 1)
    puts("Poor Sereja!");
  else
    printf("%d\n", ed);
  return 0;
}
