// (n as f64).log2()
use proconio::{input, fastout};

fn yes(yes_no: bool) {
    if yes_no {
        println!("Yes");
    } else {
        println!("No");
    }
}

#[fastout]
fn main() {
    input! {
        n: u64,
    }
    println!("{}", (n as f64).log2().ceil() as u32)
}