use std::io::Read;
use std::cmp::{max, min};

fn gcd(a: u128, b: u128) -> u128 {
    if a % b == 0 {
        return b;
    }
    gcd(b, a % b)
}

fn main() {
    let mut tab = String::new();
    std::io::stdin().read_to_string(&mut tab).ok();
    let tab: Vec<u128> = tab.trim().split('\n').next().unwrap().trim().split_whitespace()
        .map(|s| s.parse().unwrap())
        .collect();
    let t = tab[0];
    let a = tab[1];
    let b = tab[2];
    let gcd = gcd(max(a, b), min(a, b));
    let lcm = a * b / gcd ;
    let a_count = 1 + t / a - if t % a == 0 { 1 } else { 0 };
    let b_count = 1 + t / b - if t % b == 0 { 1 } else { 0 };
    let lcm_count = 1 + t / lcm - if t % lcm == 0 { 1 } else { 0 };
    println!("{}", a_count + b_count - lcm_count);
}