#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(),a.end()
#define maxs(x,y) (x = max(x,y))
#define mins(x,y) (x = min(x,y))
#define limit(x,l,r) max(l,min(x,r))
#define lims(x,l,r) (x = max(l,min(x,r)))
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)),x.end())
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cout<<#x<<" = "<<x<<endl;
#define PQ(T) priority_queue<T,v(T),greater<T> >
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
inline int in() { int x; scanf("%d",&x); return x;}
template<typename T>inline istream& operator>>(istream&i,v(T)&v)
{rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const v(T)&v)
{stringstream s;rep(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>inline ostream& operator<<(ostream&o,const v(T)&v)
{if(sz(v))o<<join(v);return o;}
template<typename T1,typename T2>inline istream& operator>>(istream&i,pair<T1,T2>&v)
{return i>>v.fi>>v.se;}
template<typename T1,typename T2>inline ostream& operator<<(ostream&o,const pair<T1,T2>&v)
{return o<<v.fi<<","<<v.se;}
template<typename T>inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return 0;}
#define yn {puts("YES");}else{puts("NO");}
const int MX = 200005;

inline int d(int n, int i) { return (n+1-i)/2;}
vp raw(int h, int w) {
  vp res;
  rep(i,h)rep(j,w) res.pb(P(i,j));
  return res;
}
vp g(int h, int w, int a) {
  vp res;
  if (a%4 == 0) {
    rep(i,2)rep(j,2) {
      vp ps = g(d(h,i),d(w,j),a/4);
      for (P p : ps) {
        p.fi = p.fi*2+i;
        p.se = p.se*2+j;
        res.pb(p);
      }
    }
    return res;
  }
  if (a%2 == 1) {
    rep(i,2) {
      vp ps = raw(d(h,i),d(w,i));
      for (P p : ps) {
        p.fi = p.fi*2+i;
        p.se = p.se*2+i;
        res.pb(p);
      }
    }
    return res;
  }
  rep(i,2) {
    vp ps = raw(d(h,i),d(w,0));
    for (P p : ps) {
      p.fi = p.fi*2+i;
      p.se *= 2;
      res.pb(p);
    }
  }
  return res;
}
vp f(int h, int w, int a, int b) {
  vp res;
  if (a%4 == 0 && b%4 == 0) {
    rep(i,2)rep(j,2) {
      vp ps = f(d(h,i),d(w,j),a/4,b/4);
      for (P p : ps) {
        p.fi = p.fi*2+i;
        p.se = p.se*2+j;
        res.pb(p);
      }
    }
    return res;
  }
  if (a%4 == 0) swap(a,b);
  if (b%4) {
    vp ps = raw(d(h,0),d(w,0));
    for (P p : ps) {
      p.fi *= 2;
      p.se *= 2;
      res.pb(p);
    }
    return res;
  }
  if (a%2 == 1) {
    rep(i,2) {
      vp ps = g(d(h,i),d(w,i),b/4);
      for (P p : ps) {
        p.fi = p.fi*2+i;
        p.se = p.se*2+i;
        res.pb(p);
      }
    }
    return res;
  }
  rep(i,2) {
    vp ps = g(d(h,i),d(w,0),b/4);
    for (P p : ps) {
      p.fi = p.fi*2+i;
      p.se *= 2;
      res.pb(p);
    }
  }
  return res;
}

int main() {
  int n,a,b;
  scanf("%d%d%d",&n,&a,&b);
  vp p = f(n*2,n*2,a,b);
  int N = n*n;
  // sort(rng(p)); uni(p);
  // if (sz(p) >= N) puts("OK");
  // return 0;
  // cerr<<sz(p)<<" "<<N<<endl;
  rep(i,N) {
    printf("%d %d\n",p[i].fi,p[i].se);
  }
  return 0;
}






















Measured memory_bytes: 2420