#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd_skip() while(*rp++>=48)
#define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define rd_signed() ({int _s=*rp=='-'&&++rp,_v=rd();_s?-_v:_v;})
#define wt(v) ({unsigned _z=v;do*--wp=_z%10+48;while(_z/=10);})
#define wt1(v) ({char wbuf[64],*wp=wbuf+sizeof wbuf;wt(v);write(1,wp,wbuf+sizeof wbuf-wp);})
#define rep4(v,s,e,t) for(typeof(e) v=s;v<e;v+=t)
#define chmax(v,a) (v=v>=a?v:a)

int xy[400];

int f1(){
	int n=0;
	rd_init();
	rd_skip();
	while(*rp){
		xy[n++]=rd_signed();
	}
	return n;
}

int f2(int n){
	int b=0;
	rep4(i,0,n,2){
		int rx=xy[i+0];
		int ry=xy[i+1];
		rep4(j,i+2,n,2){
			int lx=xy[j+0]-rx;
			int ly=xy[j+1]-ry;
			int o=ly*rx-lx*ry;
			if(lx|ly){
				int c=0;
				rep4(k,0,n,4){
					int px=xy[k+0];
					int py=xy[k+1];
					int qx=xy[k+2];
					int qy=xy[k+3];
					c+=(lx*py-ly*px+o)*(lx*qy-ly*qx+o)<=0;
				}
				chmax(b,c);
			}
		}
	}
	return b;
}

int main(){
	wt1(f2(f1()));
	_exit(0);
}