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

namespace NGS
{
    class Program
    {
        static void Main(string[] args)
        {
            var inputs = Console.ReadLine().Split(' ');

            var a1 = Double.Parse(inputs[0]);
            var a2 = Double.Parse(inputs[1]);
            var a3 = Double.Parse(inputs[2]);

            var denominator = a2 - a3;
            var numerator = a1 - a2;
            var result = (Int64)((a3 * ((denominator) / (numerator))) + (a2 - (((denominator) / (numerator)) * a1)));

            Console.Write(result + "\n");
        }
    }
}