#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[100000], i, j, k, n, x, d, bx[101], bd[101], r, t;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> x >> d;
    bx[i] = x;
    bd[i] = d + x;
  }
  j = 0;
  for (i = 0; i < n; i++) {
    x = bx[i];
    d = bd[i];
    for (r = i + 1; r < n; r++) {
      if (x == bd[r] && d == bx[r]) j = 1;
    }
  }
  if (j == 1)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}
