using System; 

namespace _3_задание 

{ 

 class Program 

 { 

 static void Main() 

 { 

 Console.WriteLine("Введите E"); 

 Console.Write("E= "); 

 double E = double.Parse(Console.ReadLine()); 

 double n = 1; 

 double m = 1; 

 double p = Math.Pow(-2, n) / m; 

 double sum = p; 

 while (Math.Abs(p)>E) 

 { 

 n = n + 1; 

 m = 1; 

 for (int i = 0; i <= n; i++) 

 { 

 m = m * i; 

 } 

 Console.WriteLine("m= ", m); 

 p = Math.Pow(-2, n) / m; 

 Console.WriteLine("p= ", p); 

 sum = sum + p; 

 }

Console.WriteLine("sum= ", sum); 

 } 

 } 

}