Speeding

#include <iostream>

using namespace std;

int main()
{
    long long a,b,x,y,n,t,c,d;
    cin>>t;
    n=0;
    t=t-1;
    cin>>x>>y>>a>>b;



    while(t>0)
    {
        c=b-y;
        d=a-x;


        if(c/d>n)
        {
            n=c/d;

        }

        x=a;
        y=b;
        t=t-1;
        if(t==0){
            break;
        }
        cin>>a>>b;


    }

    cout<<n<<endl;

    return 0;
}