#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


int N;
vector<int> A, B;

void init() {
  A.clear();
  B.clear();
}
void ae(int u, int v) {
  A.push_back(u);
  B.push_back(v);
}

bool solve() {
  init();
  if (N == 1) {
    return true;
  } else if (N <= 5) {
    return false;
  } else if (N == 6) {
    ae(0, 1);
    ae(1, 2);
    ae(2, 0);
    ae(1, 3);
    ae(2, 4);
    ae(4, 5);
    return true;
  } else {
    const int n = (N == 7) ? N : (N - 1);
    ae(0, 1);
    ae(0, 2);
    ae(2, 3);
    {
      int p = 0;
      for (int u = 4; u < n; ++u) {
        ae(p, u);
        p = u;
      }
    }
    return true;
  }
}

int main() {
  for (; ~scanf("%d", &N); ) {
    const bool res = solve();
    if (res) {
      const int M = A.size();
      puts("YES");
      printf("%d\n", M);
      for (int i = 0; i < M; ++i) {
        printf("%d %d\n", A[i] + 1, B[i] + 1);
      }
    } else {
      puts("NO");
    }
  }
  return 0;
}