#include <iostream>
#include <cmath>
#include <bits/stdc++.h>

using namespace std;

int main()
{
    double x, v,o;
    double s,s1,s2,a,t1,t2,t,tmin;
    double g = 9.81;


    cin >> x >> v >> o;

    double orad = o*M_PI/180;
    a = (-1)*g*tan(orad);

    if(x == 0)
    {
        cout << 0;
        return 0;
    }
    if (x>0)
    {
        if (o>0)
        {
            if(v == 0)
            {
                tmin = sqrt(x/a*(-1));
                tmin *= 2;
                cout << tmin;
                return 0;
            }
            else
            {
                s1 = (v*v)/(2*(-1)*a);
                s = s1+x;
                t1 = (2*s1)/v;
                t2 = sqrt(s/((-1)*a));
                tmin = 2*t2+t1;
            }
        }
        if (o<0)
        {
            if (v==0)
            {
                tmin = sqrt(x/a);
                tmin *= 2;
                cout << tmin;
                return 0;
            }
            else
            {
                s1 = (v*v)/(2*a);
                s = s1+x;
                t1 = (2*s1)/v;
                t2 = sqrt(s/a);
                t = 2*t2+t1;
                tmin = t-(2*t1);
            }
        }
    }
    if (x<0)
    {
        if(v == 0)
        {
            tmin = sqrt(x/a);
            tmin *= 2;
            cout << tmin;
            return 0;
        }
        if (o>0)
        {
            if (v==0)
            {
                tmin = sqrt(x/a);
                tmin *= 2;
                cout << tmin;
                return 0;
            }
            else
            {
                s1 = (v*v)/(2*a);
                s = s1+x;
                t1 = (2*s1)/v;
                t2 = sqrt(s/a);
                tmin = 2*t2+t1;
            }
        }
        if (o<0)
        {
            if (v == 0)
            {
                tmin = sqrt(x/(a*(-1)));
                tmin *= 2;
                cout << tmin;
                return 0;
            }
            else
            {
                s1 = (v*v)/(2*(-1)*a);
                s = s1+x;
                t1 = (2*s1)/v;
                t2 = sqrt(s/((-1)*a));
                t = 2*t2+t1;
                tmin = t-(2*t1);
            }
        }
    }
    cout << tmin;
}