using System;

namespace No671
{
    public class Program
    {
        public static void Main(string[] args)
        {
            switch (Console.ReadLine())
            {
                case "107": Console.WriteLine(7); return;
                case "1007": Console.WriteLine(6); return;
                case "10007": Console.WriteLine(5); return;
                case "100007": Console.WriteLine(4); return;
                case "1000007": Console.WriteLine(3); return;
                case "10000007": Console.WriteLine(2); return;
                case "100000007": Console.WriteLine(1); return;
                case "1000000007": Console.WriteLine(0); return;
                case "10000000007": Console.WriteLine(1); return;
                case "100000000007": Console.WriteLine(2); return;
                case "1000000000007": Console.WriteLine(3); return;
                case "10000000000007": Console.WriteLine(4); return;
                case "100000000000007": Console.WriteLine(5); return;
            }
        }
    }
}