#include <bits/stdc++.h>
using namespace std;
int a, b, l;
double f(double x) { return cos(x) * (b * tan(x) + a - l * sin(x)); }
struct Tprogram {
  void open() {
    freopen("1.in", "r", stdin);
    freopen("1.out", "w", stdout);
  }
  void close() {}
  void init() {}
  void work() {
    double w, S = 0, T = acos(0), s, t;
    scanf("%d%d%d", &a, &b, &l);
    if (a > b) a ^= b ^= a ^= b;
    if (l <= b)
      w = l <= a ? l : a;
    else
      for (int i = 100; i--; (w = f(s)) > f(t) ? S = s : (T = t))
        s = (S * 2 + T) / 3, t = (S + T * 2) / 3;
    printf(w > 1e-7 ? "%.9f\n" : "My poor head =(\n", w);
  }
} Program;
int main() {
  Program.init();
  Program.work();
  return 0;
}
