#include <bits/stdc++.h>
using namespace std;
template <class T>
T abs(T x) {
  return x > 0 ? x : -x;
}
const double pi = 2 * asin(1.0);
int n;
int m;
double a, b, p;
double calc(double ang) {
  double x = cos(ang) * p;
  double y = sin(ang) * p;
  return -((a - x) * (b - y) - a * b) / p;
}
int main() {
  cin >> a >> b >> p;
  double l = 0, r = pi / 2;
  for (int it = 0; it < 200; it++) {
    double s1 = l + (r - l) / 3;
    double s2 = l + 2 * (r - l) / 3;
    double f1 = calc(s1);
    double f2 = calc(s2);
    if (f1 < f2)
      r = s2;
    else
      l = s1;
  }
  double res = min(calc((l + r) / 2), p);
  if (p < max(a, b) + 1e-9) res = max(res, min(a, b));
  if (res < 0)
    printf("My poor head =(\n");
  else
    printf("%.10f\n", min(res, p));
  return 0;
}
