/* * J1K7_7 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef pair pii; typedef pair pll; typedef vector vi; typedef vector vll; #define left(x) (x << 1) #define right(x) (x << 1) + 1 #define mid(l, r) ((l + r) >> 1) #define mp make_pair #define pb push_back #define all(a) a.begin(),a.end() #define debug(x) {cerr <<#x<<" = " < inline bool ispow2(T x){return (x!=0 && (x&(x-1))==0);} //0 or 1 template inline T powmod(T a,T b,T mod) {ll res = 1; while(b){if(b&1) res = (res*a)%mod;a = (a*a)%mod;b >>= 1;}return res;} template inline T gcd(T a,T b){ll t;while(b){a=a%b;t=a;a=b;b=t;}return a;} template inline T lcm(T a,T b){return a/gcd(a,b)*b;} inline int nextint(){ int x; scanf("%d",&x); return x; } inline ll nextll(){ ll x; scanf("%lld",&x); return x; } const int mod=1e9+7; const ll mx_ll = numeric_limits :: max(); const int mx_int = numeric_limits :: max(); const long double PI = (long double)(3.1415926535897932384626433832795); int main() { ios_base::sync_with_stdio(false); cin.tie(0); int n; cin >> n; int x[n],y[n]; for(int i = 0; i < n; i++) { cin >> x[i] >> y[i] ; } set xx; for(int i = 0; i < n; i++) { xx.insert(x[i]); } set yy; for(int i = 0; i < n; i++) { yy.insert(y[i]); } if(xx.size() == 1 || yy.size() == 1) { cout << "YES" ; } else { cout << "NO" ; } return 0; }