codewars/go/stepik/course_2/strings/strings.go

package main

import (
	"fmt"
)

func main() {
	foo1()
}

func foo1() {
	var val rune
	fmt.Scanf("%c", &val)
	// fmt.Println(string(val))
	if val >= '0' && val <= '9' {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}