#include<bits/stdc++.h>
#include "parks.h"
#define cs const
#define pb push_back
using namespace std;
typedef vector<int> vi;
typedef long long ll;
typedef pair<int, int> pi;
cs int N = 4e5 + 5;
int n, fa[N];
map<int, int> c[N], e[N];
vector<pi> E;
int fnd(int x) {
if(x == fa[x]) return x;
return fa[x] = fnd(fa[x]);
}
void mer(int a, int b) {
if(a < 0) return;
if(fnd(a) == fnd(b)) return;
E.pb(pi(a, b));
e[a][b] = e[b][a] = E.size() - 1;
fa[fnd(a)] = fnd(b);
}
vector<int> G[N];
int dfn[N], low[N], tim;
int s[N], top, in[N], blk[N], m;
void dfs(int x) {
dfn[x] = low[x] = ++ tim;
s[++top] = x, in[x] = 1;
for(int v : G[x]) {
if(!dfn[v]) dfs(v), low[x] = min(low[x], low[v]);
else if(in[v] && dfn[v] < low[x]) low[x] = dfn[v];
}
if(low[x] == dfn[x]) {
++ m; do {
in[s[top]] = 0;
blk[s[top]] = m;
} while(s[top--] != x);
}
}
#ifdef FSYo
void build(vi u, vi v, vi a, vi b) {
int m = u.size();
cout << m << endl;
// map<pi, int> tt;
// for(int i = 0; i < m; i++) {
// cout <<i<<' '<< x[u[i]] << " " << y[u[i]] << ' ' << x[v[i]] << ' ' << y[v[i]] << ' ' << a[i] << ' ' << b[i] << '\n';
// for(int v : G[i]) cout << v << ' ';cout <<endl;
// assert(tt[pi(a[i], b[i])] == 0);
// tt[pi(a[i], b[i])] = 1;
// }
}
#endif
int construct_roads(vi x, vi y) {
n = x.size();
for(int i = 0; i < n; i++)
c[x[i]][y[i]] = i + 1;
for(int i = 0; i < n; i++) fa[i] = i;
for(int x = 2; x <= 2e5; x += 2)
for(auto p : c[x]) {
int y = p.first, t = p.second;
mer(c[x - 2][y] - 1, t - 1);
mer(c[x][y - 2] - 1, t - 1);
}
if(E.size() < n - 1) return 0;
for(int i = 0; i < n - 1; i++) {
int u = E[i].first, v = E[i].second;
if(x[u] != x[v]) continue;
if(y[u] > y[v]) swap(u, v);
int a = c[x[u] - 2][y[u]] - 1, z = -1;
if(~a) z = e[a][u];
if(~z) {
G[i].pb(z);
G[z + n - 1].pb(i + n - 1);
}
z = -1;
a = c[x[u] + 2][y[u]] - 1;
if(~a) z = e[a][u];
if(~z) {
G[i + n - 1].pb(z);
G[z + n - 1].pb(i);
}
z = -1;
a = c[x[v] - 2][y[v]] - 1;
if(~a) z = e[a][v];
if(~z) {
G[i].pb(z + n - 1);
G[z].pb(i + n - 1);
}
z = -1;
a = c[x[v] + 2][y[v]] - 1;
if(~a) z = e[a][v];
if(~z) {
G[i + n - 1].pb(z + n - 1);
G[z].pb(i);
}
z = -1;
a = c[x[u] + 2][y[u]] - 1;
int b = c[x[v] + 2][y[v]] - 1;
if(~a && ~b) z = e[a][b];
if(~z) {
G[i + n - 1].pb(z + n - 1);
G[z].pb(i);
}
}
for(int i = 0; i < n - 1; i++) {
int u = E[i].first, v = E[i].second;
if(y[u] != y[v]) continue;
if(x[u] > x[v]) swap(u, v);
int a = c[x[u]][y[u] + 2] - 1, z = -1;
int b = c[x[v]][y[v] + 2] - 1;
if(~a && ~b) z = e[a][b];
if(~z) {
G[i + n - 1].pb(z + n - 1);
G[z].pb(i);
}
}
for(int i = 0; i < (n - 1) * 2; i++)
if(!dfn[i]) dfs(i);
vi u(n - 1), v(n - 1), a(n - 1), b(n - 1);
for(int i = 0, o; i < n - 1; i++) {
u[i] = E[i].first, v[i] = E[i].second;
o = blk[i + n - 1] < blk[i];
if(x[u[i]] == x[v[i]]) {
b[i] = min(y[u[i]], y[v[i]]) + 1;
a[i] = x[u[i]] + (o ? 1 : -1);
}
else {
a[i] = min(x[u[i]], x[v[i]]) + 1;
b[i] = y[u[i]] + (o ? 1 : -1);
}
}
build(u, v, a, b);
return 1;
}
#ifdef FSYo
int main() {
freopen("1.in", "r", stdin);
// freopen("1.out", "w", stdout);
int n;
cin >> n;
vi x(n), y(n);
for(int i = 0; i < n; i++)
scanf("%d%d", &x[i], &y[i]);
if(construct_roads(x, y)) {
puts("YES");
}
else puts("NO");
return 0;
}
#endif
