use std::io::{Read,self};

fn main(){
    let mut buf = String::new();
    io::stdin().read_to_string(&mut buf).unwrap();
    let mut input = buf.split_ascii_whitespace();

    let budget:usize = input.next().unwrap().parse().unwrap();
    let kojiki:usize = input.next().unwrap().parse().unwrap();
    
    let amount_senen = budget / 1000;
    println!("{}",amount_senen / kojiki * 1000);
}