import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.complex, std.container, std.math, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


int N, A, B;
real[] X, Y;

int calc(real d) {
  int cnt;
  foreach (i; 0 .. N) foreach (j; i + 1 .. N) {
    if ((X[i] - X[j])^^2 + (Y[i] - Y[j])^^2 <= d^^2) {
      ++cnt;
    }
  }
  return cnt;
}

void doIt(int l, int x, int y, int r, int s0, int s1, int dir) {
  debug {
    writefln("N = %d, A = %d, B = %d; B' = %d", N, A, B, N * (N - 1) / 2 - B);
    writefln("  l = %d, x = %d, y = %d, r = %d; s0 = %d, s1 = %d, dir = %d", l, x, y, r, s0, s1, dir);
  }
  
  /*
    |--------20----|
        |----20--------|
      l          x   1   y
  */
  enum real C = 1e-4;
  enum real D = 1e-4 * tan(1.0);
  debug {
    writefln("  C = %.10f", C);
    writefln("  D = %.10f", D);
  }
  
  X = new real[N];
  Y = new real[N];
  foreach (i; 0 .. l) {
    X[i] = C * i;
    Y[i] = 0.0;
  }
  foreach (j; 0 .. x) {
    X[l + j] = 18.0 - D * j;
    Y[l + j] = 0.0;
  }
  X[l + x] = 20.0 + C * (r - 0.5);
  Y[l + x] = 0.0;
  foreach (j; 0 .. y) {
    X[l + x + 1 + j] = 25.0;
    Y[l + x + 1 + j] = 0.0;
  }
  
  debug {
    writeln("  X = ", X);
    writeln("  Y = ", Y);
    writeln("  10: ", calc(10.0));
    writeln("  20: ", calc(20.0));
  }
  assert(calc(10.0) == s0);
  assert(calc(20.0) == B);
  
  int now = calc(10.0);
  foreach (j; 0 .. x) {
    real t0 = 18.0 + C * j;
    real t1 = 8.0 + C * j;
    Tuple!(real, int)[] events;
    events ~= tuple(t0, 0);
    events ~= tuple(t1, 0);
    foreach (i; 0 .. j + x) {
      real t = X[i] + 10.0;
      if (t1 <= t && t <= t0) {
        events ~= tuple(t, +1);
      }
    }
    foreach (i; j + x + 1 .. N) {
      real t = X[i] - 10.0;
      if (t1 <= t && t <= t0) {
        events ~= tuple(t, -1);
      }
    }
    sort(events);
    debug {
      writeln("  events = ", events);
    }
    const eventsLen = cast(int)(events.length);
    int mx = now, cur;
    int hm;
    cur = now;
    foreach_reverse (h; 1 .. eventsLen) {
      cur += events[h][1];
      if (chmax(mx, cur)) {
        hm = h;
      }
    }
    bool ok;
    cur = now;
    foreach_reverse (h; 1 .. eventsLen) {
      cur += events[h][1];
      if (cur == A) {
        ok = true;
        X[l + j] = (events[h][0] + events[h - 1][0]) / 2.0;
        break;
      }
    }
    if (ok) {
      break;
    }
    X[l + j] = (events[hm][0] + events[hm - 1][0]) / 2.0;
    now = mx;
  }
  assert(calc(10.0) == A);
  assert(calc(20.0) == B);
}

void main() {
  debug {
    foreach (n; 1 .. 50) {
      foreach (b; (n * (n - 1) + 3) / 4 + n .. n * (n - 1) / 2 + 1) {
        // writefln("n = %d, b = %d", n, b);
        int mn = n * n, mx = 0;
        foreach (l; 0 .. n + 1) {
          foreach (x; 0 .. (n - l - 1) + 1) {
            const y = n - l - 1 - x;
            foreach (r; 0 .. l + 1) {
              if (n * (n - 1) / 2 - b == 0 * x + r + l * y) {
                const scores = [
                    l * (l - 1) / 2 + (n - l) * (n - l - 1) / 2,
                    (l + x) * (l + x - 1) / 2 + (n - l - x) * (n - l - x - 1) / 2
                ];
                if (scores[0] <= scores[1]) {
                  foreach (score; scores) {
                    chmin(mn, score);
                    chmax(mx, score);
                  }
                }
              }
            }
          }
        }
        // writefln("  [%d, %d]", mn, mx);
        foreach (a; (n * (n - 1) + 3) / 4 .. b - n + 1) {
          assert(mn <= a && a <= mx);
        }
      }
    }
  }
  
  try {
    for (; ; ) {
      N = readInt();
      A = readInt();
      B = readInt();
      
      foreach (l; 0 .. N + 1) {
        foreach (x; 0 .. (N - l - 1) + 1) {
          const y = N - l - 1 - x;
          int r = N * (N - 1) / 2 - B;
          if (y > 0) {
            r %= y;
          }
          if (0 <= r && r <= l && N * (N - 1) / 2 - B == 0 * x + r + l * y) {
            int s0 = l * (l - 1) / 2 + (N - l) * (N - l - 1) / 2;
            int s1 = (l + x) * (l + x - 1) / 2 + (N - l - x) * (N - l - x - 1) / 2;
            if (s0 <= A && A <= s1) {
              doIt(l, x, y, r, s0, s1, 0);
              goto done;
            }
            /*
            if (s1 <= A && A <= s0) {
              doIt(l, x, y, r, s0, s1, 1);
              goto done;
            }
            */
          }
        }
      }
      assert(false);
     done:
      foreach (i; 0 .. N) {
        writefln("%.10f %.10f", X[i], Y[i]);
      }
    }
  } catch (EOFException e) {
  }
}