var xyh = Console.ReadLine().Split(" ").Select(Int64.Parse).ToArray();
var x = xyh[0] * 1000;
var y = xyh[1] * 1000;
var h = xyh[2];
var items = new HashSet<(Int64, Int64, Int64)>();
items.Add((x, y, h));
var cnt = -1;
while (items.Count() > 0) {
    cnt += 1;
    var nextItems = new HashSet<(Int64, Int64, Int64)>();
    foreach (var (cx, cy, ch) in items) {
        if (cx > ch) {
            if (cx % 2 == 0) {
                nextItems.Add((cx / 2, cy, 2 * ch));
            } else {
                nextItems.Add((cx, 2 * cy, 4 * ch));
            }
        }
        if (cy > ch) {
            if (cy % 2 == 0) {
                nextItems.Add((cx, cy / 2, 2 * ch));
            } else {
                nextItems.Add((2 * cx, cy, 4 * ch));
            }
        }
    }
    items = nextItems;
}
Console.WriteLine(cnt);