#include <bits/stdc++.h>
using namespace std;
using lint = long long;
template<class T = int> using V = vector<T>;
template<class T = int> using VV = V< V<T> >;

int main() {
  cin.tie(nullptr); ios::sync_with_stdio(false);
  int n, a, b; cin >> n >> a >> b;

  V<double> x;
  auto cnt = [&](double v = 1e10) -> pair<int, int> {
    x.push_back(v);
    int s = 0, t = 0, m = x.size();
    int r = 0;
    for (int l = 0; l < m; ++l) {
      while (r < m and x[r] - x[l] <= 10) {
        ++r;
      }
      s += r - l - 1;
    }
    r = 0;
    for (int l = 0; l < m; ++l) {
      while (r < m and x[r] - x[l] <= 20) {
        ++r;
      }
      t += r - l - 1;
    }
    x.pop_back();
    return {s, t};
  };

  auto chk = [&](double th) -> bool {
    V<double>().swap(x);
    x.push_back(0);
    for (int i = 1; i < n; ++i) {
      double ng = x.back() + th, ok = 1e5;
      for (int _ = 0; _ < 100; ++_) {
        double mid = (ng + ok) / 2;
        int s, t;
        tie(s, t) = cnt(mid);
        (s <= a and t <= b ? ok : ng) = mid;
      }
      x.push_back(ok);
    }
    int s, t;
    tie(s, t) = cnt();
    cerr << s << ' ' << t << '\n';
    if (s == a and t == b) {
      for (auto e : x) {
        cout << e << ' ' << 0 << '\n';
      }
      exit(0);
    }
    return s >= a;
  };

  double ok = 1e-10, ng = 30;
  for (int _ = 0; _ < 100; ++_) {
    double mid = (ok + ng) / 2;
    (chk(mid) ? ok : ng) = mid;
  }
}