#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("unroll-loops")
//#pragma warning(disable : 4996)

#ifdef _MSC_VER
#include <intrin.h>
#define __builtin_popcount __popcnt
#define __builtin_popcountll __popcnt64
#endif

#include <limits.h>
#include <math.h>
#include <time.h>

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m - 1; i >= n; --i)
#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v, n) reverse(v, v + n);
#define VREVERSE(v) reverse(v.begin(), v.end())
#define ll long long
#define print(x) cout << (x) << '\n'
#define pe(x) cout << (x) << " "
#define DEBUG(x) cout << #x << ": " << x << endl
#define lb(v, n) lower_bound(v.begin(), v.end(), (n))
#define ub(v, n) upper_bound(v.begin(), v.end(), (n))
#define int long long
#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v) REP(i, v.size()) cout << v[i] << ((i == v.size() - 1) ? "\n" : " ")
template <typename T1, typename T2> inline void chmin(T1& a, T2 b) {
	if (a > b) a = b;
}
template <typename T1, typename T2> inline void chmax(T1& a, T2 b) {
	if (a < b) a = b;
}
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef array<int, 3> arr3;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 998244353;
constexpr int MAX = 500050;
const double pi = acos(-1);
constexpr double EPS = 1e-8;
constexpr ll LINF = 1e18 + 1;
constexpr int INF = 1e9 + 1;
//int dx[4] = { 0,0,-1,1 }, dy[4] = { 1,-1,0,0 };
void no() {
	cout << -1 << endl;
	exit(0);
}

void solve() {
	int K, X, Y; cin >> K >> X >> Y;
	if (abs(X + Y) % 2 == 1 && K % 2 == 0)no();
	int x = 0, y = 0;
	auto greedy = [&]() {
		int dx = X - x, dy = Y - y;
		int rem = K;
		int nx = x, ny = y;
		if (abs(dx) >= rem) {

			if (dx > 0)nx = x + rem;
			else nx = x - rem;
			rem = 0;
		}
		else {
			rem -= abs(dx);
			nx = x + dx;
		}
		if (dy > 0)ny = y + rem;
		else ny = y - rem;
		x = nx, y = ny;
	};
	auto adjust = [&]() {
		int prex = x, prey = y;
		int d = abs(X - x) + abs(Y - y);
		int nx = x, ny = y;
		if (d % 2 == 0) {
			int dx = X - x, dy = Y - y;
			if (abs(dx) >= abs(dy)) {
				nx = x + ((dx > 0) ? d / 2 : -d / 2);
				ny = y + ((dy > 0) ? -(K - d / 2) : K - d / 2);
			}
			else {
				ny = y + (dy > 0 ? d / 2 : -d / 2);
				nx = x + (dx > 0 ? -(K - d / 2) : K - d / 2);
			}
			x = nx, y = ny;
		}
		else {
			int dx = X - x, dy = Y - y;
			if (abs(dx) >= abs(dy)) {
				nx = x + ((dx > 0) ? d / 2 : -d / 2);
				ny = y + ((dy > 0) ? -(K - d / 2) : K - d / 2);
			}
			else {
				ny = y + (dy > 0 ? d / 2 : -d / 2);
				nx = x + (dx > 0 ? -(K - d / 2) : K - d / 2);
			}
			x = nx, y = ny;
		}


	};
	auto goal = [&]() {
		x = X, y = Y;
	};
	vector<pii>ans;
	while (x != X || y != Y) {
		int dist = abs(X - x) + abs(Y - y);
		if (dist == K)goal();
		else if (dist > 2 * K) {
			//cerr << "greedy" << endl;
			greedy();
		}
		else {
			//cerr << "adjust" << endl;
			adjust();
		}
		ans.push_back({ x,y });
		//pe(x); print(y);
	}
	print(ans.size());
	for (auto p : ans) {
		cout << p.first << " " << p.second << '\n';
	}

}





signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	mt.seed((int)(time(0)));
	//int q;
	//cin >> q;
	//while (q--)
	solve();
}



Measured memory_bytes: 7404