c#函数调用问题，怎么改成静态，求帮忙

using System;

namespace ConsoleApp4
{
class program
{

    static void Main(string[] args)
    {
        int c=0; int x; int y;
        x = Convert.ToInt32(Console.ReadLine());
        y = Convert.ToInt32(Console.ReadLine());
        c = A(x,y);
        Console.WriteLine("c");
    }
    public int A(int a ,int b)
    {
        if (a > b)
        {
            return a;
        }
        else return b;
    }
}

}错误提示适用于非静态，请问怎么解决

public int A(int a ,int b)
->
public static int A(int a ,int b)