Problem:
Score : 100 points

Problem Statement

An uppercase or lowercase English letter \alpha will be given as input.
If \alpha is uppercase, print A; if it is lowercase, print a.

Constraints

\alpha is an uppercase (A - Z) or lowercase (a - z) English letter.

Input

Input is given from Standard Input in the following format:

α

Output

If \alpha is uppercase, print A; if it is lowercase, print a.

Sample Input 1

B

Sample Output 1

A

B is uppercase, so we should print A.

Sample Input 2

a

Sample Output 2

a

a is lowercase, so we should print a.

Solution in Go (1.14.1) (judge verdict: Wrong Answer)

package main

import (
	"fmt"
	"strings"
	"unicode"
)

func main() {
	var s string
	fmt.Scan(&s)
	if isUpper(s) {
		fmt.Println(strings.ToLower(s))
	} else {
		fmt.Println(strings.ToUpper(s))
	}
}

func isUpper(v string) bool {
	r := rune(v[0])
	return unicode.IsUpper(r)
}