package main

import (
  "bufio"
  "fmt"
  _ "math"
  "os"
  _ "reflect"
  "regexp"
  "strconv"
  _ "strings"
)                                                                                                     
func main() {
  scanner := bufio.NewScanner(os.Stdin)
  th := 0
  lines := []string{}
  for scanner.Scan() {
    th += 1
    text := scanner.Text()
    lines = append(lines, text)
    if th == 2 {
      break
    }                                                                                                   }
  a, ae := strconv.ParseInt(lines[0], 10, 64)
  b, be := strconv.ParseInt(lines[1], 10, 64)
  if ae != nil || be != nil || a > 12345 || b > 12345 || (len(lines[0]) > 1 && regexp.MustCompile(`^0{1,}`).MatchString(lines[0])) || (len(lines[1]) > 1 && regexp.MustCompile(`^0{1,}`).MatchString(lines[1])) {
    fmt.Println("NG")
  } else {
    fmt.Println("OK")
  }
}