#![allow(unused_imports)]
use std::cmp::*;
use std::collections::*;
use std::io::Write;
use std::ops::Bound::*;

#[allow(unused_macros)]
macro_rules! debug {
    ($($e:expr),*) => {
        #[cfg(debug_assertions)]
        $({
            let (e, mut err) = (stringify!($e), std::io::stderr());
            writeln!(err, "{} = {:?}", e, $e).unwrap()
        })*
    };
}

fn main() {
    let n = read::<i64>();
    let mut ans = n + 1;
    let mut buffer = vec![];

    // debug!(with_p(2, 2));
    for di in 1i64..1000001 {
        for i in 2.. {
            if (di + 1).pow(i) > n + 1 {
                break;
            }

            let criterion = |mid: i64| -> bool {
                if mid == 1 {
                    return true;
                }
                if mid == n + 1 {
                    return false;
                }
                with_p(n, mid, &mut buffer);
                if buffer.len() != i as usize {
                    return buffer.len() > i as usize;
                }
                for &num in &buffer {
                    if num < di {
                        return false;
                    }
                    if num > di {
                        return true;
                    }
                }
                false
            };

            let (_, ng) = binary_search(1, n + 1, criterion);
            /*
            if di == 1 && i == 3 {
                debug!(ng);
                debug!(criterion(1));
                debug!(criterion(2));
            }
            */

            let mut criterion2 = |mid: i64| -> bool {
                with_p(n, mid, &mut buffer);
                if buffer.len() != i as usize {
                    return false;
                }
                return buffer.iter().all(|&e| e == di);
            };
            if criterion2(ng) && ng < ans {
                ans = ng;
            }
        }
    }

    println!("{}", ans);
}

type Input = i64;
fn binary_search<F>(lb: Input, ub: Input, mut criterion: F) -> (Input, Input)
where
    F: FnMut(Input) -> bool,
{
    assert_eq!(criterion(lb), true);
    assert_eq!(criterion(ub), false);
    let mut ok = lb;
    let mut ng = ub;
    while ng - ok > 1 {
        let mid = (ng + ok) / 2;
        if criterion(mid) {
            ok = mid;
        } else {
            ng = mid;
        }
    }
    (ok, ng)
}

fn with_p(mut n: i64, p: i64, buffer: &mut Vec<i64>) {
    buffer.clear();
    while n > 0 {
        buffer.push(n % p);
        n /= p;
    }
    buffer.reverse();
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}