#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-9;
const double pi = 3.14159265358979323846;
double a, b, l, w;
double get(double x) { return cos(x) * (a - l * sin(x) + b * tan(x)); }
int main() {
  int i;
  double L, R, lm, rm;
  scanf("%lf%lf%lf", &a, &b, &l);
  if (a > b) swap(a, b);
  if (l <= b)
    w = l < a ? l : a;
  else {
    L = 0;
    R = pi / 2;
    for (i = 0; i < 100; ++i) {
      lm = (L + L + R) / 3;
      rm = (L + R + R) / 3;
      if (get(lm) > get(rm))
        L = lm;
      else
        R = rm;
    }
    w = get(L);
  }
  if (w > eps)
    printf("%.10lf\n", w);
  else
    puts("My poor head =(");
  return 0;
}
