use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        mut n:usize
    }
    let mut u = vec![];
    for i in 12..100 {
        let a = i / 10;
        let b = i % 10;
        if a != 0 && a < b {
            u.push(i);
        }
    }
    n -= 1;
    let cnt = n / u.len();
    n %= u.len();
    let b = u[n] % 10;
    print!("{}", u[n]);
    for _ in 0..cnt {
        print!("{}", b);
    }
    println!();
}

#[macro_export]
macro_rules! min {
    ($a:expr $(,)*) => {{
        $a
    }};
    ($a:expr, $b:expr $(,)*) => {{
        cmp::min($a, $b)
    }};
    ($a:expr, $($rest:expr),+ $(,)*)=>{{
        cmp::min($a,min!($($rest),+))
    }}
}
#[macro_export]
macro_rules! max {
    ($a:expr $(,)*) => {{
        $a
    }};
    ($a:expr, $b:expr $(,)*) => {{
        cmp::min($a, $b)
    }};
    ($a:expr, $($rest:expr),+ $(,)*)=>{{
        cmp::min($a,min!($($rest),+))
    }}
}
#[macro_export]
macro_rules! chmin{
    ($base:expr, $($cmps:expr),+ $(,)*)=>{{
        let cmp_min = min!($($cmps),+);
        if $base > cmp_min{
            $base = cmp_min;
            true
        }else{
            false
        }
    }}
}
#[macro_export]
macro_rules! chmax{
    ($base:expr, $($cmps:expr),+ $(,)*)=>{{
        let cmp_max = max!($($cmps),+);
        if $base < cmp_min{
            $base = cmp_min;
            true
        }else{
            false
        }
    }}
}