> #include <stdio.h>
> int main()
> {
>  double v,addt,t;
>  long int i,n,min,t1;
> 
>  while (1)
>    {
>      scanf ("%ld",&n);
>      if (n==0)
>        break;
>      min=30000;
>      for(i=1;i<=n;i++)
>         {
>          scanf ("%lf%lf",&v,&addt);
>          if(addt<0)
>           continue;
>          t=4500*3.6/v+addt;
>          if(t-(long int)t==0)
>             t1=(long int)t;
>          else
>             t1=(long int)t +1;
>          if(t1<min)
>            min=t1;    
>         }
>      printf ("%ld\n",min); 
>    }
> }