Problem:
Score : 600 points

Problem Statement

Given is a positive integer N.

We will choose an integer K between 2 and N (inclusive), then we will repeat the operation below until N becomes less than K.

Operation: if K divides N, replace N with N/K; otherwise, replace N with N-K.

In how many choices of K will N become 1 in the end?

Constraints

2 \leq N \leq 10^{12}

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the number of choices of K in which N becomes 1 in the end.

Sample Input 1

6

Sample Output 1

3

There are three choices of K in which N becomes 1 in the end: 2, 5, and 6.

In each of these choices, N will change as follows:

When K=2: 6 \to 3 \to 1

When K=5: 6 \to 1

When K=6: 6 \to 1

Sample Input 2

3141

Sample Output 2

13

Sample Input 3

314159265358

Sample Output 3

9

Solution in Rust (1.15.1) (judge verdict: Accepted)

// This code is generated by [cargo-atcoder](https://github.com/tanakh/cargo-atcoder)
// Original source code:
/*
use procontools::prelude::*;

fn main() {
    input! {
    n:u64,
        }
    if n == 2 {
        p!(1);
        return;
    }
    let vn = f(n)
        .iter()
        .filter(|&&x| x != 1 && (g(n, x) - 1) % x == 0)
        .count();
    let vnm = f(n - 1).len();
    p!(vn + vnm - 1);
}
fn f(n: u64) -> Vec<u64> {
    let mut result = vec![];
    let limit = (n as f64).sqrt() as u64 + 1;
    for i in 1..n {
        if i > limit {
            return result;
        }
        if n % i == 0 {
            if i > n / i {
                return result;
            }
            if i == n / i {
                result.push(i);
                return result;
            }
            result.push(i);
            result.push(n / i);
        }
    }
    result
}
fn g(n: u64, k: u64) -> u64 {
    let mut n = n;
    if k == 1 {
        return n;
    }
    while n % k == 0 {
        n /= k;
    }
    n
}
*/

fn main() {
    let exe = "/tmp/binFE012AA0";
    std::io::Write::write_all(&mut std::fs::File::create(exe).unwrap(), &decode(BIN)).unwrap();
    std::fs::set_permissions(exe, std::os::unix::fs::PermissionsExt::from_mode(0o755)).unwrap();
    std::process::exit(std::process::Command::new(exe).status().unwrap().code().unwrap())
}

fn decode(v: &str) -> Vec<u8> {
    let mut ret = vec![];
    let mut buf = 0;
    let mut tbl = vec![64; 256];
    for i in 0..64 { tbl[TBL[i] as usize] = i as u8; }
    for (i, c) in v.bytes().filter_map(|c| { let c = tbl[c as usize]; if c < 64 { Some(c) } else { None } }).enumerate() {
        match i % 4 {
            0 => buf = c << 2,
            1 => { ret.push(buf | c >> 4); buf = c << 4; }
            2 => { ret.push(buf | c >> 2); buf = c << 6; }
            3 => ret.push(buf | c),
            _ => unreachable!(),
        }
    }
    ret
}

const TBL: &'static [u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
const BIN: &'static str = "<base64-encoded ELF executable removed>";