12. Trade Commissions

// 0 ≤ s ≤ 500 ; 500 < s ≤ 1 000 ; 1 000 < s ≤ 10 000 ; s > 10 000
// Sofia 5% 7% 8% 12%
// Varna 4.5% 7.5% 10% 13%
// Plovdiv 5.5% 8% 12% 14.5%

string city = Console.ReadLine();
double sales = double.Parse(Console.ReadLine());
double commission = 0;

//Sofia
if (city == "Sofia")
{
    if (sales <= 500)
    {
        commission = sales * 0.05;
    }
    else if (sales > 500 && sales <= 1000)
    {
        commission = sales * 0.07;
    }
    else if (sales > 1000 && sales <= 10000)
    {
        commission = sales * 0.08;
    }
    else if (sales > 10000)
    {
        commission = sales * 0.12;
    }
}

//Varna
else if (city == "Varna")
{
    if (sales <= 500)
    {
        commission = sales * 0.045;
    }
    else if (sales > 500 && sales <= 1000)
    {
        commission = sales * 0.075;
    }
    else if (sales > 1000 && sales <= 10000)
    {
        commission = sales * 0.10;
    }
    else if (sales > 10000)
    {
        commission = sales * 0.13;
    }
}

//Plovdiv
else if (city == "Plovdiv")
{
    if (sales <= 500)
    {
        commission = sales * 0.055;
    }
    else if (sales > 500 && sales <= 1000)
    {
        commission = sales * 0.08;
    }
    else if (sales > 1000 && sales <= 10000)
    {
        commission = sales * 0.12;
    }
    else if (sales > 10000)
    {
        commission = sales * 0.145;
    }
}


if (city != "Sofia" && city != "Plovdiv" && city != "Varna" || sales < 0)
{
    Console.WriteLine("error");
}
else if (commission > 0)
{
    Console.WriteLine($"{commission:F2}");
}