#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-7;
double L, R, m1, m2, a, b, l;
double calc(double alp) {
  return a * sin(alp) + b * cos(alp) - l * sin(alp) * cos(alp);
}
int main() {
  scanf("%lf%lf%lf", &a, &b, &l);
  if (a > b) swap(a, b);
  if (l <= b) {
    printf("%.8lf\n", min(l, a));
    return 0;
  }
  L = 0;
  R = acos(-1) / 2;
  while (R - L > eps) {
    m1 = (2 * L + R) / 3;
    m2 = (L + 2 * R) / 3;
    if (calc(m1) > calc(m2))
      L = m1;
    else
      R = m2;
  }
  L = min(calc(L), l);
  if (L < eps)
    puts("My poor head =(");
  else
    printf("%.8lf\n", L);
  return 0;
}
