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

public class P1010 {
    public static void Main() {
        var xyh = Console.ReadLine().Trim().Split(' ').Select(int.Parse).ToList();
        var x = xyh[0] * 1000L;
        var y = xyh[1] * 1000L;
        var h = xyh[2];
        var cands = new Queue<(int, int, int)>();
        var used = new HashSet<(int, int, int)>();
        var target = (x: 0, y: 0, h: h);
        cands.Enqueue(target);
        used.Add(target);
        while (cands.Count() > 0) {
            target = cands.Dequeue();
            if(x > target.h * (1 << target.x)) {
                var next = (target.x + 1, target.y, target.h * 2);
                if(!cands.Contains(next)) {
                    cands.Enqueue(next);
                    used.Add(next);
                }
            }
            if(y > target.h * (1 << target.y)) {
                var next = (target.x, target.y + 1, target.h * 2);
                if(!cands.Contains(next)) {
                    cands.Enqueue(next);
                    used.Add(next);
                }
            }
        }
        Console.WriteLine(target.x + target.y);
    }
}