#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>#include <algorithm>#include <cmath>using namespace std;#define maxn 10005struct Rider{ double s; int t;}rider[maxn];int n, length = 4500;bool operator < (const Rider &a, const Rider &b){ return a.t + length * 3.6 / a.s < b.t + length * 3.6 / b.s;}void input(){ for (int i = 0; i < n; i++) scanf("%lf%d", &rider[i].s, &rider[i].t);}int main(){ while (scanf("%d", &n), n) { input(); sort(rider, rider + n); int i = 0; while (rider[i].t < 0) i++; printf("%.0fn", ceil(rider[i].t + length * 3.6/ rider[i].s)); } return 0;}
