using System;

public class Program

{

    public static void Main()

    {

            var heightAboveSeaLevel = 30;

            var temperature = 3.1;

            var degLatitude = 59.284611;

            var sensorPressure = 970.3;

​

            var t1 = temperature < -7 ? 0.500 * temperature + 275.0 : (temperature < 2 ? 0.535 * temperature + 275.6 : 1.07 * temperature + 274.5);

            var b = 0.034163 * (1 - 0.0026373 * Math.Cos(2 * degLatitude));

            Console.WriteLine(sensorPressure * Math.Exp(heightAboveSeaLevel * b / t1));

    }

}