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#include <cstdio>
using namespace std;

long long int fib[45];

int left[100];
int right[100];
int used = 0;

// Function for extended Euclidean Algorithm  
long long int gcdExtended(long long int a, long long int b, long long int *x, long long int *y)  
{  
    // Base Case  
    if (a == 0)  
    {  
        *x = 0;  
        *y = 1;  
        return b;  
    }  
  
    long long int x1, y1; // To store results of recursive call  
    long long int gcd = gcdExtended(b%a, a, &x1, &y1);  
  
    // Update x and y using results of  
    // recursive call  
    *x = y1 - (b/a) * x1;  
    *y = x1;  
  
    return gcd;  
} 

void build_graph(int root, int ds) {	

	if(left[root] > 0) { // musze dolozyc nowy 
		// printf("Dokladam zrodlo, dodaje krawedz %d->%d\n", root, used);
		right[root] = used;
		used++;
		build_graph(right[root], ds);
	} else {
			int prev = root;
			int prevprev;
			for(int i=1;i<ds;i++) {
				left[prev] = used;
				// printf("dodaje lewa krawedz: %d->%d\n", prev, used);
				if (i>1) {
					right[prevprev] = used;
					// printf("dodaje prawa krawedz: %d->%d\n", prevprev, used);
				}
				prevprev=prev;
				prev=used;
				used++;
			}
		
	}

}

void solve(int k, int root) {

	// printf("tuti %d %d\n", k, root);
	// jezli k jest liczba fib
	if(k == 1) {
		right[root] = 1000;
		// printf("zamykam %d\n", root);
		return;
	}

	for (int i = 0; i<45; i++) {
		if (fib[i] == k) {
			build_graph(root, i+1);	
			return;
		}
	}

	if(k == 4) {
		left[root] = used;
		right[root] = used + 1;
		left[used] = used + 1; 

		left[used+1] = used + 2;
		right[used+1] = used + 3;
		left[used+2] = used +3;

		used += 4;
		return;
	}

	if(k == 6) {
		left[root] = used;
		right[root] = used + 1;
		left[used] = used + 1; 

		left[used+1] = used + 2;
		right[used+1] = used + 3;
		left[used+2] = used +3;

		right[used+2] = used+4;
		left[used+3] = used+4;

		used += 5;
		return;
	}
	
	for(int i = 2; i<42;i++) {
		if(fib[i+1] > k) continue;
		long long int x,y;
		gcdExtended(fib[i], fib[i+1], &x, &y);
		x*=k;
		y*=k;
		// x0 = x + fib[i+1]*t > 0
		// y0 = y - fib[i]*t > 0
		if(-1*x/fib[i+1]+1 < y/fib[i]) {
			int t = -1*x/fib[i+1]+1;
			x = x + t*fib[i+1];
			y = y - t*fib[i];
			// printf("%lld * [%lld] + %lld * [%lld] = %d\n", x, fib[i], y, fib[i+1], k);
			// printf("%lld*%lld + %lld*%lld\n", x, fib[i], y,fib[i+1]);
			// printf("Buduje graf z korzenia do fib[%d], czyli %lld\n", i+1, fib[i+1]);
			build_graph(root, i+2);
			int new_root = used;
			// printf("Rozwiązuje z wezla %d dajacy %lld krawedzi\n", new_root-2, x);
			solve(x, new_root-2);
			// printf("Rozwiązuje z wezla %d dajacy %lld krawedzi\n", new_root-1, y);
			solve(y, new_root-1);
			break;
		}
	}
}

int main(int argc, char const *argv[])
{
	int k;
	scanf("%d", &k);
	fib[0] = fib[1]= 1;
	for (int i = 2; i < 50; ++i) {
		fib[i] = fib[i-1] + fib[i-2];
		// printf("%d %lld\n", i, fib[i]);
	}

	for(int i=0;i<100;i++) {
		left[i] = right[i] = -1;
	}

	used=1; // root
	if(k <= 3) {
		build_graph(0, k+1);
	} else{
		if(k % 2 == 0) solve(k, 0);
		else {
			left[0] = 1;
			right[0] = 1000;
			used=2;
			solve(k-1,1);
		}
	}

	printf("%d\n", used+1);
	for(int i=0;i<used;i++) {

		printf("%d %d\n",
			left[i] == -1 ? used +1 : left[i] + 1, 
			right[i] == 1000 ? used+1 : right[i] == -1 ? -1 : right[i] + 1);
		// // if( left[i] == -1 && right[i]== -1) {
		// 	printf("%d: %d %d\n", i+1, used+1, -1);
		// } else if(right[i] == -1) {
		// 	printf("%d -1\n", left[i]+1)
		// } else 
		// 	printf("%d: %d %d\n", i+1, left[i]+1, right[i]+1);
		// }
	}
	printf("-1 -1 \n");


	return 0;
}