#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const int intmax = 0x3f3f3f3f;
const long long lldmax = 0x3f3f3f3f3f3f3f3fll;
double eps = 1e-6;
template <class T>
inline void checkmin(T &a, T b) {
  if (b < a) a = b;
}
template <class T>
inline void checkmax(T &a, T b) {
  if (b > a) a = b;
}
template <class T>
inline T sqr(T x) {
  return x * x;
}
template <class T>
inline T lowbit(T n) {
  return (n ^ (n - 1)) & n;
}
template <class T>
inline int countbit(T n) {
  return (n == 0) ? 0 : (1 + countbit(n & (n - 1)));
}
template <class T>
inline T checkmod(T n, T m) {
  return (n % m + m) % m;
}
inline int rand(int a, int b) {
  if (a >= b) return a;
  return rand() % (b - a) + a;
}
template <class T>
inline T lcm(T a, T b) {
  if (a < 0) return lcm(-a, b);
  if (b < 0) return lcm(a, -b);
  return a * (b / gcd(a, b));
}
template <class T>
inline T gcd(T a, T b) {
  if (a < 0) return gcd(-a, b);
  if (b < 0) return gcd(a, -b);
  return (b == 0) ? a : gcd(b, a % b);
}
template <class T>
inline T euclid(T a, T b, T &x, T &y) {
  if (a < 0) {
    T d = euclid(-a, b, x, y);
    x = -x;
    return d;
  }
  if (b < 0) {
    T d = euclid(a, -b, x, y);
    y = -y;
    return d;
  }
  if (b == 0) {
    x = 1;
    y = 0;
    return a;
  } else {
    T d = euclid(b, a % b, x, y);
    T t = x;
    x = y;
    y = t - (a / b) * y;
    return d;
  }
}
template <class T>
inline vector<pair<T, int> > factorize(T n) {
  vector<pair<T, int> > R;
  for (T i = 2; n > 1;) {
    if (n % i == 0) {
      int C = 0;
      for (; n % i == 0; C++, n /= i)
        ;
      R.push_back(make_pair(i, C));
    }
    i++;
    if (i > n / i) i = n;
  }
  if (n > 1) R.push_back(make_pair(n, 1));
  return R;
}
template <class T>
inline bool isPrimeNumber(T n) {
  if (n <= 1) return false;
  for (T i = 2; i * i <= n; i++)
    if (n % i == 0) return false;
  return true;
}
template <class T>
inline T eularFunction(T n) {
  vector<pair<T, int> > R = factorize(n);
  T r = n;
  for (int i = 0; i < R.size(); i++) r = r / R[i].first * (R[i].first - 1);
  return r;
}
template <class T>
inline int dblcmp(T a, const T b) {
  a -= b;
  return a > eps ? 1 : (a < -eps ? -1 : 0);
}
template <class T>
inline int sgn(T a) {
  return a > eps ? 1 : (a < -eps ? -1 : 0);
}
const int N = 110000;
double x[N], y[N];
pair<double, int> idx[N], idy[N];
int rx[N], ry[N];
bool flag[N];
int n;
double tl[N], tr[N], dl[N], dr[N];
void init() {
  int l, r, t;
  l = n + 1, r = 0;
  tl[0] = dl[0] = 1e12;
  tr[0] = dr[0] = -1e12;
  tl[n + 1] = dl[n + 1] = 1e12;
  tr[n + 1] = dr[n + 1] = -1e12;
  for (int i = 1; i <= n; ++i) {
    t = rx[idy[i].second];
    checkmin(l, t);
    checkmax(r, t);
    tl[i] = idx[l].first;
    tr[i] = idx[r].first;
  }
  l = n + 1, r = 0;
  for (int i = n; i >= 1; --i) {
    t = rx[idy[i].second];
    checkmin(l, t);
    checkmax(r, t);
    dl[i] = idx[l].first;
    dr[i] = idx[r].first;
  }
}
bool judge(double len) {
  int j = 1, k = 1;
  double r, l;
  for (int i = 1; i <= n; ++i) {
    while (idy[k].first < idy[i].first - eps) ++k;
    while (j <= n && idy[j].first <= idy[i].first + len) ++j;
    if (k == 1 && j == n + 1) return true;
    r = max(tr[k - 1], dr[j]);
    l = min(tl[k - 1], dl[j]);
    if (r - l <= len) return true;
  }
  return false;
}
int main() {
  double l, r;
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    scanf("%lf %lf", &l, &r);
    x[i] = l + r;
    y[i] = l - r;
    idx[i] = make_pair(x[i], i);
    idy[i] = make_pair(y[i], i);
  }
  sort(idx + 1, idx + 1 + n);
  sort(idy + 1, idy + 1 + n);
  for (int i = 1; i <= n; ++i) {
    rx[idx[i].second] = i;
    ry[idy[i].second] = i;
  }
  init();
  l = 0;
  r = 1e11;
  while (r > 1e-7) {
    r /= 2;
    if (!judge(l + r)) {
      l += r;
    }
  }
  printf("%.9lf\n", l / 2);
  return 0;
}
