#include <bits/stdc++.h>
int a, b, L;
inline double calc(double t) { return cos(t) * (b - L * sin(t) + a * tan(t)); }
int main() {
  scanf("%d%d%d", &a, &b, &L);
  double l = 0, r = acos(0);
  if (a > b) a = a + b, b = a - b, a = a - b;
  while (r - l > 1e-8) {
    double tl = l + (r - l) / 3, tr = r - (r - l) / 3;
    if (calc(tl) < calc(tr))
      r = tr;
    else
      l = tl;
  }
  double ans = L;
  if (calc(l) < ans) ans = calc(l);
  if (L <= b) ans = L > a ? a : L;
  if (calc(l) < 1e-8)
    printf("My poor head =(\n");
  else
    printf("%.8lf\n", ans);
}
