#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1.0);
const double EPS = 1e-10;
int a, b, l;
double calc(double j) { return b * cos(j) - l * sin(j) * cos(j) + a * sin(j); }
double cal(double j) { return a / cos(j) + b / sin(j); }
int main() {
  scanf("%d%d%d", &a, &b, &l);
  double x = 0;
  double ll = 0, rr = PI / 2, mid1, mid2;
  while (ll + EPS < rr) {
    mid1 = (ll + rr) / 2;
    mid2 = (mid1 + rr) / 2;
    double ans1 = cal(mid1);
    double ans2 = cal(mid2);
    if (ans2 > ans1)
      rr = mid2;
    else
      ll = mid1;
  }
  double L = cal(ll);
  if (l >= L) {
    printf("My poor head =(\n");
    return 0;
  }
  if (a < b) swap(a, b);
  if (l <= a) {
    printf("%d\n", min(b, l));
    return 0;
  }
  ll = 0;
  rr = PI / 2;
  while (ll + EPS < rr) {
    mid1 = (ll + rr) / 2;
    mid2 = (mid1 + rr) / 2;
    double ans1 = calc(mid1);
    double ans2 = calc(mid2);
    if (ans2 > ans1)
      rr = mid2;
    else
      ll = mid1;
  }
  printf("%.7lf\n", calc(mid2));
  return 0;
}
