#include <bits/stdc++.h>
#define ld long double
using namespace std;
 
int a, b, f;
ld height(ld x)
{
    return 1.0*a*cos(x) - 1.0*f*cos(x)*sin(x) + 1.0*b*sin(x);
}
 
int main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
 
    cin >> a >> b >> f;
    if(f <= max(a, b))
    {
        cout << min(f, min(a, b));
        return 0;
    }
    ld l = 0, r = 1.57;
    for(int i=0; i<60; i++)
    {
        ld d = (r-l)/3.0;
        ld m1 = l+d, m2 = l+2*d;
        ld u = height(m1),
            v = height(m2);
        if(u < v)   r = m2;
        else        l = m1;
    }
    if(height(l) < 0)
    {
        cout << "My poor head =(";
        return 0;
    }
    cout << setprecision(15) << height(l);
 
    return 0;
}