package main

import (
	"fmt"
	"regexp"
	"strconv"
)

func main() {
	var A, B string
	reg := regexp.MustCompile(`^((0)|([1-9][0-9]{1,4}))$`)
	fmt.Scan(&A, &B)
	a, _ := strconv.Atoi(A)
	b, _ := strconv.Atoi(B)
	if reg.MatchString(A) && reg.MatchString(B) && a <= 12345 && b <= 12345 {
		fmt.Println("OK")
	} else {
		fmt.Println("NG")
	}
}