import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) throw new EOFException; tokens = readln.split; } auto token = tokens[0]; tokens.popFront; return token; }
int readInt() { return readToken().to!int; }
long readLong() { return readToken().to!long; }
real readReal() { return readToken().to!real; }

void chmin(T)(ref T t, in T f) { if (t > f) t = f; }
void chmax(T)(ref T t, in T f) { if (t < f) t = f; }

int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = cast(int)(as.length); for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a < val)); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a <= val)); }


long floor(long a, long m) {
  return a / m - ((a % m < 0) ? 1 : 0);
}
long ceil(long a, long m) {
  return a / m + ((a % m > 0) ? 1 : 0);
}


immutable INF = 10L^^18;

int N;
long[] A, B;

void main() {
  try {
    for (; ; ) {
      N = readInt();
      A = new long[N];
      B = new long[N];
      foreach (i; 0 .. N) {
        A[i] = readLong();
        B[i] = readLong();
      }
      
      long opt = INF;
      long ans = -1;
      void check(long x) {
        if (x <= 0) {
          return;
        }
        long min = +INF, max = -INF;
        foreach (i; 0 .. N) {
          const y = A[i] + B[i] * x;
          chmin(min, y);
          chmax(max, y);
        }
        if (opt > max - min || (opt == max - min && ans > x)) {
          opt = max - min;
          ans = x;
        }
      }
      
      check(1);
      foreach (i; 0 .. N) foreach (j; i + 1 .. N) {
        long a = A[j] - A[i];
        long b = B[j] - B[i];
        if (b != 0) {
          if (b < 0) {
            a *= -1;
            b *= -1;
          }
          foreach (x; [floor(-a, b), ceil(-a, b)]) {
            check(x);
          }
        }
      }
      
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}