// yukicoder 180 美しいWhitespace (2)
// 2019.8.10 bal4u

#include <stdio.h>

typedef long long ll;

#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif

int in() {   // 非負整数の入力
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

int a[1004], b[1004], N;

ll f(int x) {
	int i; ll mi, ma, t;
	mi = ma = a[0] + (ll)b[0]*x;
	for (i = 1; i < N; i++) {
		t = a[i] + (ll)b[i]*x;
		if (t < mi) mi = t;
		else if (t > ma) ma = t;
	}
	return ma-mi;
}
		
int search(int r) {
	int l = 0, m1, m2, pl, pr;
	ll f1, f2;
	pl = -1;
    while (l != pl || r != pr) {
		pl = l, pr = r;
		m1 = (2*(ll)l + r)/3, m2 = (l+2*(ll)r)/3;
		f1 = f(m1); if (f1 == 0) return m1;
		f2 = f(m2); if (f2 == 0) return m2;
		if (f1 <= f2) r = m2; else l = m1;
    }
	return f1 <= f2? m1: m2;
}
	
int main()
{
	int i, ma;

	N = in(), ma = 0;
	for (i = 0; i < N; i++) {
		a[i] = in(), b[i] = in();
		if (a[i] > ma) ma = a[i];
	}
	if (f(1) == 0) puts("1");
	else printf("%d\n", search(ma+1));
	return 0;
}