cbj

/*
 Author: 曹北健(37509)
 Result: AC Submission_id: 4148175
 Created at: Sat Mar 12 2022 10:34:40 GMT+0800 (China Standard Time)
 Problem: 5395  Time: 14    Memory: 1680
*/

#include <stdio.h>
int main(){
double x[1024], y[1024], maxslope = -1e12, slope0;
    int n, i, j;
    scanf("%d", &n);
    for(i = 0;i < n;i++){
        scanf("%lf%lf", &x[i], &y[i]);
    }
    for(i = 0;i < n;i++){
        for(j = i + 1;j < n;j++){
            slope0 = (y[j] - y[i]) / (x[j] - x[i]);
            if(slope0 > maxslope){
                maxslope = slope0;
            }
        }
    }
    printf("%.3f\n", maxslope);
return 0;
}