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
// Artur Kraska, II UWr

#include <bits/stdc++.h>

#define forr(i, n)                  for(int i=0; i<n; i++)
#define FOREACH(iter, coll)         for(auto iter = coll.begin(); iter != coll.end(); ++iter)
#define FOREACHR(iter, coll)        for(auto iter = coll.rbegin(); iter != coll.rend(); ++iter)
#define lbound(P,R,PRED)            ({typeof(P) X=P,RRR=(R), PPP = P; while(PPP<RRR) {X = (PPP+(RRR-PPP)/2); if(PRED) RRR = X; else PPP = X+1;} PPP;})
#define testy()                     int _tests; scanf("%d", &_tests); FOR(_test, 1, _tests)
#define CLEAR(tab)                  memset(tab, 0, sizeof(tab))
#define CONTAIN(el, coll)           (coll.find(el) != coll.end())
#define FOR(i, a, b)                for(int i=a; i<=b; i++)
#define FORD(i, a, b)               for(int i=a; i>=b; i--)
#define MP                          make_pair
#define PB                          push_back
#define ff                          first
#define ss                          second
#define deb(X)                      X;

#define M 1000000007
#define INF 1000000007LL

using namespace std;

vector <int> res[105];

int main()
{
    int n = 91, k;
    scanf("%d", &k);
    FOR(i, 1, 29)
        res[i].PB(i+1);
    FOR(i, 31, 60)
        res[i].PB(i+31);
    FOR(i, 61, 90)
    {
        res[i].PB(i+1);
        res[i].PB(i-30);
    }
    for(int i=30; k>0; i--)
    {
        if(k&1)
            res[i].PB(i+30);
        k /= 2;
    }
    FOR(i, 1, n)
        while(res[i].size() < 2)
            res[i].PB(-1);
    printf("%d\n", n);
    FOR(i, 1, n)
    {
        //cout << i << ": ";
        printf("%d %d\n", res[i][0], res[i][1]);
    }

    return 0;
}