#include <bits/stdc++.h>
using namespace std;
double pi = acos(-1.0);
double eps = 1e-18;
double limit = -1e10;
int main() {
double zlr;
bool you_are_bastard = 0;
for(double T_T = 0.0; ; T_T -= 1e5) {
zlr = T_T;
if(you_are_bastard) {
double OvO = tan(pi / 2.0 - eps);
zlr = OvO;
break;
}
if(zlr < limit) {
you_are_bastard = 1;
}
}
cout << zlr << endl;
return 0;
}