#![allow(unused_parens)]
#![allow(unused_imports)]
#![allow(non_upper_case_globals)]
#![allow(non_snake_case)]
#![allow(unused_mut)]
#![allow(unused_variables)]
#![allow(dead_code)]

type Vec2<T> = Vec<Vec<T>>;
type Vec3<T> = Vec<Vec<Vec<T>>>;

#[allow(unused_macros)]
macro_rules! invec {
    ( $ t : ty ) => {{
        let mut s = String::new();
        match std::io::stdin().read_line(&mut s) {
            Ok(0) => Vec::<$t>::new(),
            Ok(n) => s
                .trim()
                .split_whitespace()
                .map(|s| s.parse::<$t>().unwrap())
                .collect::<Vec<$t>>(),
            Err(_) => Vec::<$t>::new(),
        }
    }};
}

#[allow(unused_macros)]
macro_rules! get {
      ($t:ty) => {
          {
              let mut line: String = String::new();
              std::io::stdin().read_line(&mut line).unwrap();
              line.trim().parse::<$t>().unwrap()
          }
      };
      ($($t:ty),*) => {
          {
              let mut line: String = String::new();
              std::io::stdin().read_line(&mut line).unwrap();
              let mut iter = line.split_whitespace();
              (
                  $(iter.next().unwrap().parse::<$t>().unwrap(),)*
              )
          }
      };
      ($t:ty; $n:expr) => {
          (0..$n).map(|_|
              get!($t)
          ).collect::<Vec<_>>()
      };
      ($($t:ty),*; $n:expr) => {
          (0..$n).map(|_|
              get!($($t),*)
          ).collect::<Vec<_>>()
      };
      ($t:ty ;;) => {
          {
              let mut line: String = String::new();
              std::io::stdin().read_line(&mut line).unwrap();
              line.split_whitespace()
                  .map(|t| t.parse::<$t>().unwrap())
                  .collect::<Vec<_>>()
          }
      };
      ($t:ty ;; $n:expr) => {
          (0..$n).map(|_| get!($t ;;)).collect::<Vec<_>>()
      };
}

#[allow(unused_macros)]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let mut s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};

    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
    ($iter:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[allow(unused_macros)]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };

    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };

    ($next:expr, [$t:tt]) => {
        {
            let len = read_value!($next, usize);
            (0..len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
        }
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };

    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };

    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

#[allow(unused_macros)]
#[cfg(debug_assertions)]
macro_rules! mydbg {
    //($arg:expr) => (dbg!($arg))
    //($arg:expr) => (println!("{:?}",$arg));
      ($($a:expr),*) => {
          eprintln!(concat!($(stringify!($a), " = {:?}, "),*), $($a),*);
      }
}
#[cfg(not(debug_assertions))]
macro_rules! mydbg {
    ($($arg:expr),*) => {};
}

macro_rules! echo {
    ($($a:expr),*) => {
          $(println!("{}",$a))*
      }
}

use std::cmp::*;
use std::collections::*;
use std::ops::{Add, Div, Mul, Rem, Sub};

trait SafeRangeContain {
    fn safe_contains(&self, x: i64) -> bool;
}

impl SafeRangeContain for std::ops::Range<usize> {
    fn safe_contains(&self, x: i64) -> bool {
        if x < 0 {
            return false;
        }
        return self.contains(&(x as usize));
    }
}

#[allow(dead_code)]
static INF_I64: i64 = i64::max_value() / 2;
#[allow(dead_code)]
static INF_I32: i32 = i32::max_value() / 2;
#[allow(dead_code)]
static INF_USIZE: usize = usize::max_value() / 2;
#[allow(dead_code)]
static M_O_D: usize = 1000000007;
#[allow(dead_code)]
static PAI: f64 = 3.1415926535897932;

trait IteratorExt: Iterator {
    fn toVec(self) -> Vec<Self::Item>;
}

impl<T: Iterator> IteratorExt for T {
    fn toVec(self) -> Vec<Self::Item> {
        self.collect()
    }
}

trait CharExt {
    fn toNum(&self) -> usize;
    fn toAlphabetIndex(&self) -> usize;
    fn toNumIndex(&self) -> usize;
}
impl CharExt for char {
    fn toNum(&self) -> usize {
        return *self as usize;
    }
    fn toAlphabetIndex(&self) -> usize {
        return self.toNum() - 'a' as usize;
    }
    fn toNumIndex(&self) -> usize {
        return self.toNum() - '0' as usize;
    }
}

trait VectorExt {
    fn joinToString(&self, s: &str) -> String;
}
impl<T: ToString> VectorExt for Vec<T> {
    fn joinToString(&self, s: &str) -> String {
        return self
            .iter()
            .map(|x| x.to_string())
            .collect::<Vec<_>>()
            .join(s);
    }
}

trait StringExt {
    fn get_reverse(&self) -> String;
}
impl StringExt for String {
    fn get_reverse(&self) -> String {
        self.chars().rev().collect::<String>()
    }
}

trait UsizeExt {
    fn pow(&self, n: usize) -> usize;
}
impl UsizeExt for usize {
    fn pow(&self, n: usize) -> usize {
        return ((*self as u64).pow(n as u32)) as usize;
    }
}

fn main() {
    solve();
}

#[derive(Debug)]
pub struct PrimeFactor {
    base: u64,
    exp: u64,
}
impl PrimeFactor {
    fn new(base: u64, exp: u64) -> PrimeFactor {
        PrimeFactor {
            base: base,
            exp: exp,
        }
    }
}
impl PartialEq for PrimeFactor {
    fn eq(&self, target: &Self) -> bool {
        self.base == target.base && self.exp == target.exp
    }
}
impl Eq for PrimeFactor {}
fn factraize(n: u64) -> Vec<PrimeFactor> {
    let mut tmp = n;
    let mut b = 1;
    let mut res = vec![];
    let mut count = 0;
    loop {
        b += 1;
        if (b * b > n) {
            break;
        };
        if (tmp % b == 0) {
            let mut e = 0;
            for i in 1.. {
                e = i;
                tmp = tmp / b;
                if (tmp % b != 0) {
                    break;
                };
            }
            res.push(PrimeFactor::new(b, e));
        }
    }
    if (tmp != 1) {
        res.push(PrimeFactor::new(tmp, 1));
    }
    return res;
}

struct Factraize {
    primes: Vec<u64>,
}
impl Factraize {
    fn new(M: u64) -> Self {
        let mut N = 0_usize;
        for i in 0_usize.. {
            if (i as u64 * i as u64) > M {
                N = i;
                break;
            }
        }
        let mut p = vec![false; N];

        let mut p2 = vec![];
        for i in 2..N {
            if !p[i] {
                p2.push(i as u64);
                for j in 1.. {
                    if i * j < N {
                        p[i * j] = true;
                    } else {
                        break;
                    }
                }
            }
        }

        Factraize { primes: p2 }
    }
    fn calc(&self, a: u64) -> Vec<PrimeFactor> {
        let mut ret = vec![];
        let mut a = a;
        for i in 0..self.primes.len() {
            let p = self.primes[i];
            let mut k = 0;
            while a >= p && a % p == 0 {
                k += 1;
                a /= p;
            }
            if k != 0 {
                ret.push(PrimeFactor::new(p, k));
            }
        }
        if a != 1 {
            ret.push(PrimeFactor::new(a, 1));
        }
        return ret;
    }
}

fn solve() {
    let mut ans: u64 = 0;
    let N = get!(u64);
    let a = factraize(N);
    for item in a {
        ans += item.base * item.exp;
    }

    echo!(ans);
}