#include<bits/stdc++.h>
using namespace std;
int n, tot, rd[6][6], id[6];
pair<int, int> e[15];
int main() {
    scanf("%d", &n);
    if(n == 1) {
        puts("YES\n0");
    }
    else if(n <= 4) {
        puts("NO");
    }
    else if(n == 5) {
        puts("NO");
        return 0;
        for(int i = 1; i <= 5; ++ i) {
            for(int j = i + 1; j <= 5; ++ j) {
                e[tot ++] = {i, j};
            }
        }
        int w = 0;
        for(int i = 0; i < 1 << tot; ++ i) {
            for(int j = 0; j < tot; ++ j) {
                auto [u, v] = e[j];
                rd[u][v] = rd[v][u] = (i >> j & 1);
            }
            for(int j = 1; j <= 5; ++ j) {
                id[j] = j;
            }
            int cnt = 0;
            do {
                int flg = 1;
                for(int j = 1; j <= 5 && flg; ++ j) {
                    for(int k = 1; k <= 5; ++ k) {
                        if(rd[j][k] != rd[id[j]][id[k]]) {
                            flg = 0;
                            break;
                        }
                    }
                }
                cnt += flg;
            }while(next_permutation(id + 1, id + 6));
            if(cnt == 1) {
                w = 1;
                puts("YES");
                printf("%d\n", __builtin_popcount(i));
                for(int j = 0; j < tot; ++ j) {
                    auto [u, v] = e[j];
                    if(i >> j & 1) {
                        printf("%d %d\n", u, v);
                    }
                }
                break;
            }
        }
        if(!w)
            puts("NO");
    }
    else if(n == 6) {
        puts("YES\n6\n1 2\n2 3\n1 3\n3 4\n2 5\n5 6");
    }
    else {
        puts("YES");
        printf("%d\n", n - 1);
        puts("1 2");
        puts("1 3");
        puts("3 4");
        puts("1 5");
        for(int i = 6; i <= n; ++ i) {
            printf("%d %d\n", i - 1, i);
        }
    }
}