ขอความช่วยเหลือกุรุเช็ค+ตรวจการบ้านให้หน่อยครับ - -

using System;

namespace BonusPoint1
{
	class Program
	{
		public static void Main()
		{int count=0;			
			Console.Write("Initial Value :");
			int frist = int.Parse(Console.ReadLine());
			for(int i=1;i>=1;i++)
			{
			count=count+1;
			Console.Write("Input Operator :");
			char op = char.Parse(Console.ReadLine());
			Console.Write("Input Number :");
			int no = int.Parse(Console.ReadLine());
			Console.WriteLine("Present Value = {0:f2}",calculate(frist,no,op,count));
			}
		}
		static int calculate(int a,int b,char o,int c)
		{int sum=0;
			if(o=='+')
			{
				if(c==1)
				{
					return sum=a+b;
				}
				else
				{
					return sum=sum+b;
				}
			}
			if(o=='-')
			{
				if(c==1)
				{
					return sum=a-b;
				}
				else
				{
					return sum=sum-b;
				}
			}
			if(o=='*')
			{
				if(c==1)
				{
					return sum=a*b;
				}
				else
				{
					return sum=sum*b;
				}
			}
			if(o=='/')
			{
				if(c==1)
				{
					return sum=a/b;
				}
				else
				{
					return sum=sum/b;
				}
			}
			else
			{
				Console.WriteLine("Finish Calculator \n End Value Is {0}",sum);
			}
		}
	}
}