Problem:
Problem Statement

You are given two integers a and b (a≤b). Determine if the product of the integers a, a+1, …, b is positive, negative or zero.

Constraints

a and b are integers.

-10^9≤a≤b≤10^9

Partial Score

In test cases worth 100 points, -10≤a≤b≤10.

Input

The input is given from Standard Input in the following format:

a b

Output

If the product is positive, print Positive. If it is negative, print Negative. If it is zero, print Zero.

Sample Input 1

1 3

Sample Output 1

Positive

1×2×3=6 is positive.

Sample Input 2

-3 -1

Sample Output 2

Negative

(-3)×(-2)×(-1)=-6 is negative.

Sample Input 3

-1 1

Sample Output 3

Zero

(-1)×0×1=0.

Solution in Rust (1.15.1) (judge verdict: Wrong Answer)

use std::io;
use std::str::FromStr;
use std::str::Chars;
use std::i32;
use std::u8;
use std::f64;
use std::ascii::AsciiExt;
use std::collections::HashMap;
use std::collections::HashSet;
use std::collections::BTreeMap;
use std::collections::BTreeSet;
use std::collections::VecDeque;
use std::io::prelude::*;
use std::time::Duration;
use std::cmp;

macro_rules! println_stderr(
    ($($arg:tt)*) => { {
        let r = writeln!(&mut ::std::io::stderr(), $($arg)*);
        r.expect("failed printing to stderr");
    } }
);

macro_rules! print_stderr(
    ($($arg:tt)*) => { {
        let r = write!(&mut ::std::io::stderr(), $($arg)*);
        r.expect("failed printing to stderr");
    } }
);

fn main() {
    let v = next_ints();
    if v[0] <= 0 && v[1] >= 0 {
        println!("Zero");
    }
    else if v[0] > 0 && v[1] > 0 {
        println!("Positive");
    }
    else if v[0] < 0 && v[1] < 0 {
        println!("{}",match v[1] - v[0] {
            n if n % 2 == 0 => "Positive",
            _ => "Negative",
        })
    }
}

#[allow(dead_code)]
fn next_string() -> String {
    let mut input = String::new();
    io::stdin().read_line(&mut input).unwrap();
    input
}

#[allow(dead_code)]
fn next_strings() -> Vec<String> {
    let input = next_string();
    input.split_whitespace().map(|x| x.parse().unwrap()).collect()
}

#[allow(dead_code)]
fn next_int() -> i64 {
    let input = next_string();
    i64::from_str(input.trim()).unwrap()
}

#[allow(dead_code)]
fn next_ints() -> Vec<i64> {
    let input = next_string();
    input.split_whitespace().map(|x| x.parse().unwrap()).collect()
}