using static System.Console;
using static System.Math;
public class Program {
public static void Main() => WriteLine(Atan(5) * 180 / PI);
}
//https://pt.stackoverflow.com/q/184690/101
dXNpbmcgc3RhdGljIFN5c3RlbS5Db25zb2xlOwp1c2luZyBzdGF0aWMgU3lzdGVtLk1hdGg7CgkJCQkJCnB1YmxpYyBjbGFzcyBQcm9ncmFtIHsKCXB1YmxpYyBzdGF0aWMgdm9pZCBNYWluKCkgPT4gV3JpdGVMaW5lKEF0YW4oNSkgKiAxODAgLyBQSSk7Cn0KCi8vaHR0cHM6Ly9wdC5zdGFja292ZXJmbG93LmNvbS9xLzE4NDY5MC8xMDE=