#include <iostream>
#include <stdio.h>

using namespace std;

#define MAXN 120000
#define INF 1000000000

struct coord{
    double x, y;
};
coord v[MAXN];
int out[MAXN];

bool Verificare_Unghi_Convex(coord origine, coord lastlast, coord last, coord next){

}

int main()
{
    int n, i, inext, io, min, u;
    scanf("%d", &n);
    min = INF;
    for(i = 0; i < n; i++){
        scanf("%lf%lf", &v[i].x, &v[i].y);
        if(v[i].y < min){
            min = v[i].y;
            io = i;
        }
    }
    out[0] = io + 1;
    out[1] = io + 2;
    u = 2;
    inext = io + 3;
    while((inext % n) != io){
        if(Verificare_Unghi_Convex(v[io], v[out[u - 1]], v[out[u - 2]], v[inext])){
            out[u - 1] = inext;
        }else{
            out[u] = inext;
            u++;
        }
        inext++;
    }/bamschemaeroaredecompilare
    return 0;
}