#include <bits/stdc++.h>

#pragma GCC optimize("O3")
#pragma GCC target("tune=native")
#pragma GCC target("avx")
// #pragma GCC target("avx2")
#pragma GCC optimize("unroll-loops")

using namespace std;

using i64 = int64_t;

const i64 MOD = 1e9+7;

const i64 INF = 1e18+7;

// pythonのrangeのような範囲for文用のclass for(const auto& i : Range<>(10)) のように書く
template <typename T = i64>
struct Range{
    struct iterator{
        T value;
        const T step, last;
        const T& operator*(){return value;}
        iterator(T value, T step, T last) :
            value(step < static_cast<T>(0) ? max(last, value) : min(last, value)),
            step(step),
            last(last)
        {
        }
        iterator operator++(){value = step < static_cast<T>(0) ? max(value + step, last) : min(value + step, last); return *this;}
        bool operator!=(const iterator& x){return value != x.value;}
    };
    const T start, last, step;

    Range(const T start, const T last, const T step = static_cast<T>(1)) :
        start(start),
        last(last),
        step(step)
    {
    }

    Range(const T last) :
        start(0),
        last(last),
        step(1)
    {
    }

    iterator begin(){return iterator(start, step, last);}
    iterator end(){return iterator(last, step, last);}
};

// lambda式を用いた再帰
template <typename F>
struct FixPoint{
    const F _f;
    FixPoint(F&& f) : _f(forward<F>(f)){}

    template<typename... Types>
    decltype(auto) operator()(Types&&... args) const{
        return _f(*this, forward<Types>(args)...);
    }
};

template <typename F>
static decltype(auto) makeRec(F&& f){
    return FixPoint<F>(forward<F>(f));
}

// 多次元vectorの一斉初期化 makeVector<i64, 0>(a, b, ...)のように書く
template <typename T, T Value = T()>
vector<T> makeVector(size_t x){
    return vector<T>(x, T(Value));
}

template <typename T, T Value = T(), typename... Types>
auto makeVector(size_t x, Types... args){
    return vector<decltype(makeVector<T, Value>(args...))>(x, makeVector<T, Value>(args...));
}

// 最大値を更新し、更新できた時にはtrueを返す
template <typename T = i64>
bool chmax(T& a, T b){
    if(a < b){
        a = b;
        return true;
    }
    return false;
}

// 同様に最小値を更新する
template <typename T = i64>
bool chmin(T& a, T b){
    if(a > b){
        a = b;
        return true;
    }
    return false;
}

// 行数と変数名、値をclogに表示するデバッグ用print
#define dump(x) fprintf(stderr, "line =%4d, name =%7s , ", __LINE__, #x); clog << "value = " << x << endl;

// 同様の配列向けデバッグ用print
#define vecdump(x) fprintf(stderr, "line =%4d, name =%7s\n", __LINE__, #x); _dump_macro(x);

void _dump(int, string& x){
    clog << x << endl;
}

template <typename T>
void _dump(bool, T& x){
    clog << x << " ";
}

template <typename T, typename U = typename T::iterator>
void _dump(int, T& x){

    for(auto& elm : x)
        _dump(0, elm);

    clog << endl;
}

template <typename T>
void _dump_macro(T& x){
    _dump(0, x);
}

// input用の関数群
void _input(int, string& x){
    cin >> x;
}

template <typename T>
void _input(bool, T& x){
    cin >> x;
}

template <typename T, typename U = typename T::iterator>
void _input(int, T& x){

    for(auto& elm : x)
        _input(0, elm);
}

template <typename T>
void input_single(T& x){
    _input(0, x);
}

auto input(){}

template <typename T, typename... Types>
void input(T& value, Types&&... args){
    input_single(value);
    input(forward<Types>(args)...);
};

void _pararell_input(size_t){}

template <typename T, typename... Types>
void _pararell_input(size_t index, T& value, Types&&... args){
    input(value[index]);
    _pararell_input(index, forward<Types>(args)...);
}

template <typename... Types>
void pararell_input(size_t count, Types&&... args){
    for(const auto& i : Range<>(count))
        _pararell_input(i, forward<Types>(args)...);
}


signed main(){

    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    int n, d1, d2;
    input(n, d1, d2);
    int m = n;
    n *= 2;
    auto f = [&](int d){
        vector<vector<int>> v(n, vector<int>(n, -1));

        vector<pair<int,int>> p;
        int sq = sqrt(d + 1);
        for(const auto& i : Range<>(sq + 2)){
            int po = d - i * i;
            int j = sqrt(po) + 1e-9;
            if(i * i + j * j == d)
                p.emplace_back(i, j);
        }

        auto g = makeRec([&](auto&& g, int x, int y, bool fl) -> void{
            if(v[x][y] != -1){
                assert(v[x][y] == fl);
                return ;
            }
            v[x][y] = fl;
            for(auto& q : p){
                int i, j;
                tie(i, j) = q;
                for(const auto& k : Range<>(4)){
                    int tx = x + (k & 2 ? 1 : -1) * i;
                    int ty = y + (k & 1 ? 1 : -1) * j;
                    if(tx < 0 || ty < 0 || tx >= n || ty >= n)
                        continue;
                    g(tx, ty, !fl);
                }
            }
        });

        for(const auto& i : Range<>(n))
            for(const auto& j : Range<>(n))
                if(v[i][j] == -1)
                    g(i, j, false);

        return v;
    };
    auto b1 = f(d1);
    auto b2 = f(d2);
    vector<vector<pair<int,int>>> p(4);
    for(const auto& i : Range<>(n))
        for(const auto& j : Range<>(n)){
            p[(b1[i][j] << 1) + b2[i][j]].emplace_back(i, j);
        }
    for(const auto& i : Range<>(4)){
        dump(p[i].size());
        if(p[i].size() >= m * m){
            for(const auto& j : Range<>(m * m))
                cout << p[i][j].first << " " << p[i][j].second << endl;
            return 0;
        }
    }


}


Measured memory_bytes: 28120