public class  ClMyExp
    {
        public double X { get; set; }
        public double Eps { get; set; }
        public double S { get; set; }
        public int N { get; set; }
        public double MyExpWhile()
        {
            N = 1;
            double a = X;
            double fact = 1;
            while (Math.Abs(a) > Eps)
            {
                a = Math.Pow(X,N) / fact;
                S = S + a;
                N++;
                fact = fact * N;
            }
            return S;
        }
        public double MyExpFor()
        {
            double a = X;
            double S = 0;
            N = 1;
            double fact = 1;
            for (int n = 1; Math.Abs(a) > Eps; n++)
            {
                fact = fact * n;
                a = Math.Pow(X, n) / fact;
                S = S + a;
                N++;
            }
            return S;
        }
        public double MyExpDoWhile()
        {
            N = 1;
            double a = X;
            double S = 0;
            double fact = 1;
            do
            {
                a = Math.Pow(X, N) / fact;
                S = S + a;
                N++;
                fact = fact * N;
            }
            while (Math.Abs(a) > Eps);
            return S;
        }
    }