using System; public class Program 

{   public static void Main()

{       Console.Write("Q = "); int Q = int.Parse(Console.ReadLine());

        double [] S = new double [Q+2] ;

        int [] R = new int [Q+2] ;

        int [] V = new int [Q+2] ;

        double pi = Math.PI ; Console.WriteLine("...... пи = "+"{0:F2}",+pi);

        Console.Write("A = ") ; int A = int.Parse(Console.ReadLine());

        Console.Write("B = ") ; int B = int.Parse(Console.ReadLine());

        S[0] = A*B ; Console.WriteLine("......=> S[0] = "+"{0:F2}",+S[0]);

for (int i = 1; i <= Q; i++)

    {   Console.Write("R["+i+"] = ");int N=int.Parse(Console.ReadLine());R[i]=N;

        Console.Write("V["+i+"] = ");int M=int.Parse(Console.ReadLine());V[i]=M;

        if (V[i] == 0) { S[i] =-pi*R[i]*R[i]/2; } 

   else if (V[i] == 1) { S[i] =pi*R[i]*R[i]/2; }

        S[i]=S[i-1]+S[i]; Console.WriteLine("................=> S["+i+"] = "+"{0:F2}",+S[i]);

}}}