fn main() {
    let mut xyh = String::new();
    std::io::stdin().read_line(&mut xyh).ok();
    let xyh: Vec<usize> = xyh.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let x = xyh[0] * 1000;
    let y = xyh[1] * 1000;
    let mut h = xyh[2];

    let (mut x, mut y) = (x.max(y), x.min(y));
    let mut result = 0usize;
    while y > h {
        y /= 2;
        h *= 2;
        result += 1;
    }
    while x > h {
        x /= 2;
        h *= 2;
        result += 1;
    }
    println!("{}", result);
}