using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
 
class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        string[] inpt = Reader.ReadLine().Split(' ');
        this.Stamp1 = long.Parse(inpt[0]);
        this.Stamp2 = long.Parse(inpt[1]);
        this.MinVal = long.Parse(inpt[2]);
        
        long ans = this.GetAns(this.MinVal) + this.MinVal;
        Console.WriteLine(ans);
    }
    private Dictionary<long, long> dic = new Dictionary<long, long>();
    private long GetAns(long mustVal) {
        if(dic.ContainsKey(mustVal)) {
            return dic[mustVal];
        }
        if(mustVal < 0) {
            return Math.Abs(mustVal);
        }
        long ans = this.MinVal + Math.Min(this.Stamp1, this.Stamp2);
        if(mustVal % this.Stamp1 == 0 || mustVal % this.Stamp2 == 0) {
            ans = 0;
        } else
        {
            ans = Math.Min(ans, this.GetAns(mustVal - this.Stamp1));
            ans = Math.Min(ans, this.GetAns(mustVal - this.Stamp2));
        }
        dic.Add(mustVal, ans);
        return ans;
    }
    private long Stamp1;
    private long Stamp2;
    private long MinVal;


    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"



1234 1688 10000



 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}