#include<stdio.h>#include<algorithm>using namespace std;struct node{ double time;}p[10009];int main(){ int n,i,j,v,st; while(scanf("%d",&n)!=EOF) { if(n==0) break; for(i=0,j=0;i<n;i++) { scanf("%d%d",&v,&st); if(st>=0) { p[j].time=st+(4.5*3600)/v; j++; } } for(i=1;i<j;i++) { if(p[i].time<p[0].time) swap(p[i],p[0]); } if(p[0].time-(int)p[0].time==0) printf("%.0lfn",p[0].time); else printf("%.0lfn",p[0].time+1); }}
