#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep3(i, l, n) for (int i = l; i < (n); ++i)
#define sz(v) (int)v.size()
const int inf = 1e9 + 7;
const ll INF = 1e18;
int mod = 1000000007;
#define abs(x) (x >= 0 ? x : -(x))
#define lb(v, x) (int)(lower_bound(all(v), x) - v.begin())
#define ub(v, x) (int)(upper_bound(all(v), x) - v.begin())
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { if (a < b) { a = b; return 1; } return 0; }
template<typename T> T gcd(T a, T b) { if (b == 0) return a; return gcd(b, a % b); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
template<typename T> T pow(T a, int b) { return b ? pow(a * a, b / 2) * (b % 2 ? a : 1) : 1; }
ll modpow(ll a, ll b, ll _mod) { return b ? modpow(a * a % _mod, b / 2, _mod) * (b % 2 ? a : 1) % _mod : 1; }
template<class T> ostream& operator << (ostream& os, const vector<T>& vec) { for (auto &vi: vec) os << vi << " "; return os; }
template<class T, class U> ostream& operator << (ostream& os, const pair<T, U>& p) { os << p.F << " " << p.S; return os; }
template<typename T >inline istream& operator >> (istream& is, vector<T>& v) { rep(j, sz(v)) is >> v[j]; return is; }
template<class T> inline void add(T &a, int b) { a += b; if (a >= mod) a -= mod; }


void solve();

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cout << fixed << setprecision(10);

    int T;
    // cin >> T;
    T = 1;

    while (T--) {
        solve();
    }
}

void solve() {
  int k, x, y;
  cin >> k >> x >> y;

  if (k % 2 == 0 && (x + y) % 2) {
    cout << -1 << endl;
    return;
  }
  int xflg = 0, yflg = 0, xyswap = 0;
  if (x < 0) { x = -x; xflg = 1; }
  if (y < 0) { y = -y; yflg = 1; }
  if (x < y) { swap(x, y); xyswap = 1; }

  vector<pii> ans;
  int x2 = 0, y2 = 0;
  if ((x + y) % k == 0) {
    int c = (x + y) / k;
    rep(i, c) {
      int tmp = min(x - x2, k);
      x2 += tmp;
      y2 += k - tmp;
      ans.eb(x2, y2);
    }
  } else {
    int n;
    if (x >= k) n = (x + y + (k - 1)) / k;
    else n = 2;

    if (k % 2 && (x + y) % 2 != n % 2) n++;
    int exc = (n * k - x - y) / 2;
    if (x >= k || (y + exc) % k == 0 || (y + exc) % k + x > k) {
      while (1) {
        y2 += k;
        if (y2 > y + exc) break;
        ans.eb(x2, y2);
      }
      y2 -= k;
      if (y2 != y + exc) {
        // 残り y に足す分
        int tmp = y + exc - y2;
        // 上側少なくとも 1 回通る
        x2 = k - tmp;
        y2 = y + exc;
        // 上側最初
        ans.eb(x2, y2);
      }

      while (1) {
        x2 += k;
        if (x2 > x) break;
        ans.eb(x2, y2);
      }
      x2 -= k;
      int tmp = x - x2;
      y2 -= k - tmp;
      x2 = x;
      // 右側最初
      ans.eb(x2, y2);

      if (y2 != y) {
        while (1) {
          y2 -= k;
          if (y2 < y) break;
          ans.eb(x2, y2);
        }
      }
    } else {
      ans.eb(x, x - k);
      int tmp = (y + (k - x)) / 2;
      ans.eb(x + (k - tmp), tmp - (k - x));
      ans.eb(x, y);
    }
  }

  rep(i, sz(ans)) {
    // 先に swap
    if (xyswap) swap(ans[i].F, ans[i].S);
    if (xflg) ans[i].F = -ans[i].F;
    if (yflg) ans[i].S = -ans[i].S;
  }
  cout << sz(ans) << endl;
  rep(i, sz(ans)) cout << ans[i] << endl;
}


Measured memory_bytes: 3952