Problem:
Score : 100 points

Problem Statement

Given is a lowercase English letter C that is not z. Print the letter that follows C in alphabetical order.

Constraints

C is a lowercase English letter that is not z.

Input

Input is given from Standard Input in the following format:

C

Output

Print the letter that follows C in alphabetical order.

Sample Input 1

a

Sample Output 1

b

a is followed by b.

Sample Input 2

y

Sample Output 2

z

y is followed by z.

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

#![allow(non_snake_case)]

use std::io::{stdin, Read};
use std::str::FromStr;
fn read_option<T: FromStr>() -> Option<T> {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok()
}
fn read<T: FromStr>() -> T {
    let opt = read_option();
    opt.expect("failed to parse token")
}

fn main() {
    let c: String = read();
    let ans = std::char::from_u32(c.chars().next().unwrap() as u32 + 1).unwrap_or('a');
    println!("{}", ans)
}