using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace sringformatformat__
{
    class Program
    {
        static void Main(string[] args)
        {
            float A =1.23456f;
            int Digits = 2;
            string F = string.Format(@"{0}0:f{1}{2}", '{', Digits,'}');
            Console.WriteLine(F, A);

            return;
        }
    }
}