#include <bits/stdc++.h>
using namespace std;
struct st {
  int x, d;
};
st a[1001];
int n;
bool cmp(st o, st p) { return o.x < p.x; }
void solve() {
  int i, j;
  sort(a, a + n, cmp);
  for (i = 0; i < n; i++)
    for (j = i + 1; j < n; j++)
      if (a[j].d < 0)
        if (a[j].x + a[j].d == a[i].x && a[i].x + a[i].d == a[j].x) {
          cout << "YES\n";
          return;
        }
  cout << "NO\n";
}
void input() {
  int i;
  while (cin >> n) {
    for (i = 0; i < n; i++) cin >> a[i].x >> a[i].d;
    solve();
  }
}
int main() {
  input();
  return 0;
}
