#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

inline int in()
    {
    int noRead=0;
    char c=getchar_unlocked();
    for(;c<33;){c=getchar_unlocked();};
    while(c>32)
    {
    noRead = (noRead << 3) + (noRead << 1) + (c - '0');
    c=getchar_unlocked();
    }
    return noRead;
    };
int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n=in(),x=in(),y=in(),x1=in(),y1=in(),k=x-x1,l=y-y1; 
    if(k && l)
        {
        printf("NO");
        return 0;               
    }
    else if(k && !l)
        {
         for(;n>2;n--)
            {
            x1=in();
            y1=in();
            if((y-y1))
               {
                   printf("NO");
                   return 0;
               }
         }
        printf("YES");
        return 0;               
    }
    else if(!k && l)
        {
         for(;n>2;n--)
            {
            x1=in();
            y1=in();
            if((x-x1))
               {
                   printf("NO");
                   return 0;
               }
         }
        printf("YES");
        return 0;             
    }
    else
        {
        x1=in();
        y1=in();
        k=x-x1;
        l=y-y1;
        if(k && l)
        {
        printf("NO");
        return 0;               
    }
    else if(k && !l)
        {
         for(;n>3;n--)
            {
            x1=in();
            y1=in();
            if((y-y1))
               {
                   printf("NO");
                   return 0;
               }
         }
        printf("YES");
        return 0;               
    }
    else if(!k && l)
        {
         for(;n>3;n--)
            {
            x1=in();
            y1=in();
            if((x-x1))
               {
                   printf("NO");
                   return 0;
               }
         }
        printf("YES");
        return 0;             
    }        
    }     
    return 0;
}