import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String str1 = scan.nextLine();
    String str2 = scan.next();
    String str3 = scan.next();    
    
    int num1 = Integer.parseInt(str1);
    int num2 = Integer.parseInt(str2);
    int num3 = Integer.parseInt(str3);    

    int sum = 0;
    String str4 = "";
    
    for(int i=1;i<=1000;i++) {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    }
    String str = String.valueOf(num1);
    str = str4;
    System.out.println(str);
    scan.close();    
  }
} import java.util.Scanner; Scanner java.util public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String str1 = scan.nextLine();
    String str2 = scan.next();
    String str3 = scan.next();    
    
    int num1 = Integer.parseInt(str1);
    int num2 = Integer.parseInt(str2);
    int num3 = Integer.parseInt(str3);    

    int sum = 0;
    String str4 = "";
    
    for(int i=1;i<=1000;i++) {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    }
    String str = String.valueOf(num1);
    str = str4;
    System.out.println(str);
    scan.close();    
  }
} Main public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String str1 = scan.nextLine();
    String str2 = scan.next();
    String str3 = scan.next();    
    
    int num1 = Integer.parseInt(str1);
    int num2 = Integer.parseInt(str2);
    int num3 = Integer.parseInt(str3);    

    int sum = 0;
    String str4 = "";
    
    for(int i=1;i<=1000;i++) {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    }
    String str = String.valueOf(num1);
    str = str4;
    System.out.println(str);
    scan.close();    
  } main {
    Scanner scan = new Scanner(System.in);
    String str1 = scan.nextLine();
    String str2 = scan.next();
    String str3 = scan.next();    
    
    int num1 = Integer.parseInt(str1);
    int num2 = Integer.parseInt(str2);
    int num3 = Integer.parseInt(str3);    

    int sum = 0;
    String str4 = "";
    
    for(int i=1;i<=1000;i++) {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    }
    String str = String.valueOf(num1);
    str = str4;
    System.out.println(str);
    scan.close();    
  } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String str1 = scan.nextLine(); str1 scan.nextLine() scan.nextLine scan String str2 = scan.next(); str2 scan.next() scan.next scan String str3 = scan.next(); str3 scan.next() scan.next scan int num1 = Integer.parseInt(str1); num1 Integer.parseInt(str1) Integer.parseInt Integer str1 int num2 = Integer.parseInt(str2); num2 Integer.parseInt(str2) Integer.parseInt Integer str2 int num3 = Integer.parseInt(str3); num3 Integer.parseInt(str3) Integer.parseInt Integer str3 int sum = 0; sum 0 String str4 = ""; str4 "" for(int i=1;i<=1000;i++) {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    } int i=1; int i=1; i 1 i<=1000 i 1000 i++ i++ i {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    } {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    } sum = num1 * i sum num1 * i num1 i if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      } num2 <= sum && num3 >= sum num2 <= sum num2 sum num3 >= sum num3 sum {
          str4 = "OK";
          break;
      } str4 = "OK" str4 "OK" break; str4 = "NG" str4 "NG" String str = String.valueOf(num1); str String.valueOf(num1) String.valueOf String num1 str = str4 str str4 System.out.println(str) System.out.println System.out System System.out str scan.close() scan.close scan String[] args args public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String str1 = scan.nextLine();
    String str2 = scan.next();
    String str3 = scan.next();    
    
    int num1 = Integer.parseInt(str1);
    int num2 = Integer.parseInt(str2);
    int num3 = Integer.parseInt(str3);    

    int sum = 0;
    String str4 = "";
    
    for(int i=1;i<=1000;i++) {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    }
    String str = String.valueOf(num1);
    str = str4;
    System.out.println(str);
    scan.close();    
  }
} public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String str1 = scan.nextLine();
    String str2 = scan.next();
    String str3 = scan.next();    
    
    int num1 = Integer.parseInt(str1);
    int num2 = Integer.parseInt(str2);
    int num3 = Integer.parseInt(str3);    

    int sum = 0;
    String str4 = "";
    
    for(int i=1;i<=1000;i++) {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    }
    String str = String.valueOf(num1);
    str = str4;
    System.out.println(str);
    scan.close();    
  }
} Main
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String str1 = scan.nextLine();
    String str2 = scan.next();
    String str3 = scan.next();    
    
    int num1 = Integer.parseInt(str1);
    int num2 = Integer.parseInt(str2);
    int num3 = Integer.parseInt(str3);    

    int sum = 0;
    String str4 = "";
    
    for(int i=1;i<=1000;i++) {
      sum = num1 * i;
      if(num2 <= sum && num3 >= sum) {
          str4 = "OK";
          break;
      }
      str4 = "NG";
    }
    String str = String.valueOf(num1);
    str = str4;
    System.out.println(str);
    scan.close();    
  }
}