#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 getint(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 n, m, first[2020], second[2020], xx[2020], yy[2020], flag, tp[2020];
int vst[2020][2020];
pair<int, int> p[2020];
int can(int mid) {
  int L = mid << 1;
  ++flag;
  for (int i = 0, j; i < n; i = j) {
    for (j = i; j < n; j++) {
      if (second[i] != second[j]) break;
      if (i == j) continue;
      if (first[j] - first[j - 1] > (L << 1)) break;
    }
    int x1 = first[i] - L, x2 = first[j - 1] + L, cnt = 0;
    for (int k = 0, kk; k < m; k = kk) {
      for (kk = k; kk < m; kk++) {
        if (xx[k] != xx[kk]) break;
        if (kk == k) continue;
        if (yy[kk] - yy[kk - 1] > (L << 1)) break;
      }
      if (xx[k] < x1 || xx[k] > x2) continue;
      if (yy[k] - L <= second[i] && second[i] <= yy[kk - 1] + L) {
        for (int ii = 0; ii < cnt; ii++) {
          if (vst[tp[ii]][k] == flag) return true;
          vst[tp[ii]][k] = flag;
        }
        tp[cnt++] = k;
      }
    }
  }
  return false;
}
int main() {
  int u, v;
  scanf("%d%d", &n, &m);
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &u, &v);
    p[i] = pair<int, int>(u + v, u - v);
  }
  sort(p, p + n);
  for (int i = 0; i < n; i++) second[i] = p[i].first, first[i] = p[i].second;
  for (int i = 0; i < m; i++) {
    scanf("%d%d", &u, &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 = 2000100;
  if (!can(ed)) {
    puts("Poor Sereja!");
    return 0;
  }
  while (ed - st > 1) {
    int mid = st + ed >> 1;
    if (can(mid))
      ed = mid;
    else
      st = mid;
  }
  printf("%d\n", ed);
  return 0;
}
