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
#include<bits/stdc++.h>
using namespace std;

int tab[109][3];

int main()
{
    int k,a=3,b=2,c=3,d=1;
    scanf("%d", &k);
    if(k == 1)
    {
        printf("2\n2 -1\n-1 -1\n");
        return 0;
    }
    tab[1][1] = 2;
    tab[1][2] = 3;
    for(int i=1; i<=32; i++)
    {
        if(k & d)
        {
            tab[b][1] = -2;
            tab[b][2] = a+1;
            a++;
            b = a;
            k -= d;
        }
        if(2 * d == k)
        {
            a++;
            tab[b][1] = tab[c][1] = a;
            tab[b][2] = tab[c][2] = tab[a][1] = tab[a][2] = -1;
            break;
        }
        tab[b][1] = tab[c][1] = a+1;
        tab[b][2] = tab[c][2] = a+2;
        b = a + 1;
        c = a + 2;
        a += 2;
        d *= 2;
    }
    printf("%d\n", a);
    for(int i=1; i<=a; i++)
    {
        if(tab[i][1] == -2) printf("%d %d\n", a, tab[i][2]);
        else printf("%d %d\n", tab[i][1], tab[i][2]);
    }
    return 0;
}