1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
#include <iostream>
#include <math.h>
#include <stdio.h>
#include <string>
#include <map>
#include <stdlib.h>
#include <vector>
#include <cstring>
#include <algorithm>  

using namespace std;


class Node {
    public:
    int ownNumber;
    int target1;
    int target2;     
    Node(int nubmer, int t1, int t2) {
        target1 = t1;
        target2 = t2;
        ownNumber = nubmer;
    }
};

int main() {
    int edges = 15;
	scanf("%d", &edges);

    vector<Node> map;
    map.push_back(Node(0, -1, -1));

    for (int i = 1; i < 30; i++) {
        map.push_back(Node(i, i + 1, -1));
    }
    map.push_back(Node(30, 31, -1));
    int expectedTowerElements = 28 * 2 + 3;
    map.push_back(Node(31, 32 + expectedTowerElements, -1));

    int towerElements = 3;
    map.push_back(Node(32, 30, 31));
    map.push_back(Node(33, 30, 31));
    map.push_back(Node(34, 32, 33));
    for (int j = 0 ; j < 28; j++) {
       
        map.push_back(Node(32 + towerElements, 29 + towerElements, 30 + towerElements));
        map.push_back(Node(33 + towerElements, 31 + towerElements , 32 + towerElements));
        towerElements++;
        towerElements++;
    }
    edges--;
    int currentNode = 1;
    for (int i = 0 ; i < 31; i++){
        int bit = (edges >> i) & 1;
        if (bit == 1) {
            if (i == 0) {
                map[currentNode].target2 = 33 + towerElements;
                currentNode++;
            } else {
                map[currentNode].target2 = 33 + (i - 1) * 2;
                currentNode++;
            }
        }

    }


    map.push_back(Node(32, 33 + towerElements, -1));
    map.push_back(Node(33 + towerElements, -1, -1));

    printf("%d\n", map.size() - 1);
    for (int i = 1 ; i < map.size(); i++){
        printf("%d %d\n", map[i].target1, map[i].target2);
    }

    

    return 0;
}