#include <bits/stdc++.h>
using namespace std;
int main() {
  string result;
  int n;
  long long camel[102][2];
  while (cin >> n) {
    result = "NO";
    for (int i = 0; i < n; i++)
      for (int j = 0; j < 2; j++) cin >> camel[i][j];
    for (int i = 0; i < n; i++)
      for (int j = 0; j < n; j++) {
        if (i != j) {
          if ((camel[j][0] == camel[i][0] + camel[i][1]) &&
              (camel[j][1] == -camel[i][1])) {
            result = "YES";
          }
        }
      }
    cout << result << endl;
  }
  return 0;
}
