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

namespace ConsoleApp1
{
	class Program
	{
		static void Main( string[] args )
		{
		    string[] str = Console.ReadLine().Split(' ');

			long x = long.Parse( str[0] );
			long y = long.Parse( str[1] );
			long z = long.Parse( str[2] );
			Console.WriteLine( ( z - ( x <= z ? 1 : 0 ) - ( y <= z ? 1 : 0 ) ) );
		}
	}
}