///////////////////////////////////////////////////////////////////////////////

#include <bits/stdc++.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>

using namespace std;

///////////////////////////////////////////////////////////////////////////////

#define DEBUG 0

#define pb push_back
#define V vector
#define M unordered_map
#define S static
#define PI  (3.1415926535)

#define rep(i,n) for(ll i=0LL; i<n; ++i)
#define srep(i,s,n) for(ll i=s; i<n; ++i)
#define rrep(i,n) for(ll i=n-1LL; i>=0LL; --i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define CIN(x) do { \
        assert(!cin.eof()); \
        cin >> x; \
        assert(!cin.fail()); \
} while(0);
#if DEBUG
#define debug_print(...) _debug_print(__VA_ARGS__)
#define debug_printf(...) printf(__VA_ARGS__)
#define debug_print_time _debug_print_time
#else // DEBUG
#define debug_print(...)
#define debug_printf(...)
#define debug_print_time
#endif // DEBUG

typedef long long ll;
typedef unsigned long long ull;
typedef tuple<ll, ll> t2;
typedef tuple<ll, ll, ll> t3;
typedef tuple<ll, ll, ll, ll> t4;
typedef tuple<ll, ll, ll, ll, ll> t5;
template <typename T>
using priority_queue_incr = priority_queue<T, V<T>, greater<T> >;

///////////////////////////////////////////////////////////////////////////////

template <typename TT, typename T>
T get_m(M<TT, T> &m, TT k, T default_value)
{
    if (m.find(k) == m.end()) return m[k] = default_value;
    return m[k];
}

template <typename TT, typename T>
void incr_m(M<TT, T> &m, TT k)
{
    if (m.find(k) == m.end()) m[k] = 0;
    m[k]++;
}

void llin(ll &a)
{
    CIN(a);
}

void llinl1(V<ll> &v, ll count)
{
    for (ll i = 0LL; i < count; ++i) {
        ll a;
        CIN(a);
        v.push_back(a);
    }
}

void llinl2(V<t2> &v, ll count)
{
    for (ll i = 0LL; i < count; ++i) {
        ll a, b;
        CIN(a >> b);
        v.push_back(t2(a, b));
    }
}

void llinl3(V<t3> &v, ll count)
{
    for (ll i = 0LL; i < count; ++i) {
        ll a, b, c;
        CIN(a >> b >> c);
        v.push_back(t3(a, b, c));
    }
}

void llinl4(V<t4> &v, ll count)
{
    for (ll i = 0LL; i < count; ++i) {
        ll a, b, c, d;
        CIN(a >> b >> c >> d);
        v.push_back(t4(a, b, c, d));
    }
}

void llina(V<ll> &v, ll count)
{
    llinl1(v, count);
}

template <typename T>
void sort(V<T> &v)
{
    sort(v.begin(), v.end());
}

template <typename T>
void sort_reverse(V<T> &v)
{
    sort(v.begin(), v.end(), greater<T>());
}

template <typename T>
void _debug_print(T x)
{
    cout << x << endl;
}

void _debug_print(const t2 &x)
{
    ll x1 = get<0>(x);
    ll x2 = get<1>(x);
    cout << "-- " << x1 << " -- " << x2 << endl;
}

void _debug_print(const t3 &x)
{
    ll x1 = get<0>(x);
    ll x2 = get<1>(x);
    ll x3 = get<2>(x);
    cout << "-- " << x1 << " -- " << x2 << " -- " << x3 << endl;
}

void _debug_print(const t4 &x)
{
    ll x1 = get<0>(x);
    ll x2 = get<1>(x);
    ll x3 = get<2>(x);
    ll x4 = get<3>(x);
    cout << "-- " << x1 << " -- " << x2
         << " -- " << x3 << " -- " << x4 << endl;
}

template <typename T>
void _debug_print(T xarray[], ll n)
{
    rep (i, n) _debug_print(xarray[i]);
}

template <typename T>
void _debug_print(const V<T> &xlist)
{
    for (auto x : xlist) {
        cout << "-- ";
        _debug_print(x);
    }
}

template <typename T>
void _debug_print(const set<T> &xset)
{
    for (auto x : xset) {
        cout << "-- ";
        _debug_print(x);
    }
}

template <typename TT, typename T>
void _debug_print(const M<TT, T> &xlist)
{
    for (auto x : xlist) {
        TT k = x.first;
        T v = x.second;
        cout << "====" << endl;
        cout << "K=";
        _debug_print(k);
        cout << "V=";
        _debug_print(v);
    }
}

void _debug_print_time(const char *prefix)
{
    struct timeval tv;
    gettimeofday(&tv, NULL);
    struct tm *tm = localtime(&tv.tv_sec);
    printf("-- %s %02d:%02d:%02d.%06ld\n",
           prefix, tm->tm_hour, tm->tm_min, tm->tm_sec, tv.tv_usec);
}

///////////////////////////////////////////////////////////////////////////////

void _main();
int main()
{
    cout << setprecision(12);
#if !DEBUG
    ios::sync_with_stdio(false);
    cin.tie(0);
#endif

    _main();
    return 0;
}

ll d(t2 a, t2 b)
{
    ll x1 = get<0>(a);
    ll y1 = get<1>(a);
    ll x2 = get<0>(b);
    ll y2 = get<1>(b);
    return abs(x1 - x2) + abs(y1 - y2);
}

t2 go_reverse(V<t2> &anslist, t2 aim, t2 now, ll unit)
{
    ll aim_x = get<0>(aim);
    ll aim_y = get<1>(aim);
    ll now_x = get<0>(now);
    ll now_y = get<1>(now);

    t2 next = t2(1e18, 1e18);

    if (aim_x < now_x) next = t2(now_x + unit, now_y);
    else if (aim_x > now_x) next = t2(now_x - unit, now_y);
    else if (aim_y < now_y) next = t2(now_x, now_y + unit);
    else if (aim_y > now_y) next = t2(now_x, now_y - unit);
    else assert(false);

    anslist.pb(next);
    return next;
}

t2 hole_in(V<t2> &anslist, t2 aim, t2 now, ll unit)
{
    anslist.pb(aim);
    return aim;
}

t2 driver_shot(V<t2> &anslist, t2 aim, t2 now, ll unit)
{
    ll aim_x = get<0>(aim);
    ll aim_y = get<1>(aim);
    ll now_x = get<0>(now);
    ll now_y = get<1>(now);
    ll next_x = now_x;
    ll next_y = now_y;

    ll diff_x = min(unit, abs(aim_x - now_x));
    if (diff_x) next_x += diff_x * (abs(aim_x - now_x) / (aim_x - now_x));

    ll diff_y = unit - diff_x;
    if (diff_y) next_y += diff_y * (abs(aim_y - now_y) / (aim_y - now_y));

    t2 next = t2(next_x, next_y);
    anslist.pb(next);
    return next;
}

t2 approach(V<t2> &anslist, t2 aim, t2 now, ll unit, bool even)
{
    ll aim_x = get<0>(aim);
    ll aim_y = get<1>(aim);
    ll now_x = get<0>(now);
    ll now_y = get<1>(now);
    ll remain = d(aim, now);

    ll d_to_corner = (even ? remain / 2LL : remain - unit);

    t2 corner = driver_shot(anslist, aim, now, d_to_corner);
    anslist.erase(anslist.end()-1);
    unit -= d_to_corner;
    ll corner_x = get<0>(corner);
    ll corner_y = get<1>(corner);

    t2 next = t2(1e18, 1e18);

    if (corner_x == aim_x) {
        if (now_x < aim_x) next = t2(corner_x + unit, corner_y);
        else next = t2(corner_x - unit, corner_y);
    }
    else {
        if (now_y < aim_y) next = t2(corner_x, corner_y - unit);
        else next = t2(corner_x, corner_y + unit);
    }

    anslist.pb(next);
    return next;
}

void _main()
{
    ll unit; llin(unit);
    ll x; llin(x);
    ll y; llin(y);

    t2 aim = t2(x, y);
    t2 now = t2(0, 0);

    if (!(unit & 1LL) && (d(aim, now) & 1LL)) {
        cout << -1 << endl;
        return;
    }

    S V<t2> anslist;

    while (aim != now) {
        ll remain = d(aim, now);
        if ((unit & 1LL) && remain < unit && (remain & 1LL)) {
            now = go_reverse(anslist, aim, now, unit);
        }
        else if (remain == unit) {
            now = hole_in(anslist, aim, now, unit);
        }
        else if (remain >= unit * 2LL) {
            now = driver_shot(anslist, aim, now, unit);
        }
        else if (!(remain & 1LL)) {
            now = approach(anslist, aim, now, unit, true);
        }
        else {
            assert(unit & 1LL);
            now = approach(anslist, aim, now, unit, false);
        }
    }

    debug_printf("---- ans\n");
    cout << anslist.size() << endl;
    for (auto ans : anslist) cout << get<0>(ans) << " " << get<1>(ans) << endl;
}

///////////////////////////////////////////////////////////////////////////////


Measured memory_bytes: 7328