#include<stdio.h>
int main(){
	int n,i;
	scanf("%d",&n);
	int x[n],y[n];
		for(i=0;i<n;i++){
		scanf("%d%d",&x[i],&y[i]);
		}
		int count = 0;
		double t[n],p,q;
		for(i=0;i<n;i++){
			 p=y[i+1]-y[i];
			 q=x[i+1]-x[i];
			 t[i]=p/q;
		}
		for(i=0;i<n;i++){
			if(i>0){
			if(t[i]==t[i-1])
			count++;}
		}
		if(count==n-2)
		printf("YES");
		else
		printf("NO");
	return 0;
}