import java.util.*;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		int k;
		int A;
		int B;
		  Scanner scan = new Scanner(System.in);
		  
		 // Read the next integer from the screen 
		 	k= scan.nextInt(); 
		 	
	        
	        // Read the next integer from the screen 
	        A = scan.nextInt(); 
	        
	       
	        
	        // Read the next integer from the screen 
	        B= scan.nextInt();
	        check(k,A,B);
	        }
	public static void check(int k,int A,int B)
	{
		int l=0;
		for(int i=A;i<=B;i++)
		{
			if(i%k==0)
			{
			l=1	;
			}
		}
		
		if(l==1)
		{
			System.out.print("OK");
		}
		else 
		{
			System.out.print("NG");	
		}	
	}
} import java.util.*; util.* java public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		int k;
		int A;
		int B;
		  Scanner scan = new Scanner(System.in);
		  
		 // Read the next integer from the screen 
		 	k= scan.nextInt(); 
		 	
	        
	        // Read the next integer from the screen 
	        A = scan.nextInt(); 
	        
	       
	        
	        // Read the next integer from the screen 
	        B= scan.nextInt();
	        check(k,A,B);
	        }
	public static void check(int k,int A,int B)
	{
		int l=0;
		for(int i=A;i<=B;i++)
		{
			if(i%k==0)
			{
			l=1	;
			}
		}
		
		if(l==1)
		{
			System.out.print("OK");
		}
		else 
		{
			System.out.print("NG");	
		}	
	}
} Main public static void main(String[] args) {
		// TODO Auto-generated method stub

		int k;
		int A;
		int B;
		  Scanner scan = new Scanner(System.in);
		  
		 // Read the next integer from the screen 
		 	k= scan.nextInt(); 
		 	
	        
	        // Read the next integer from the screen 
	        A = scan.nextInt(); 
	        
	       
	        
	        // Read the next integer from the screen 
	        B= scan.nextInt();
	        check(k,A,B);
	        } main {
		// TODO Auto-generated method stub

		int k;
		int A;
		int B;
		  Scanner scan = new Scanner(System.in);
		  
		 // Read the next integer from the screen 
		 	k= scan.nextInt(); 
		 	
	        
	        // Read the next integer from the screen 
	        A = scan.nextInt(); 
	        
	       
	        
	        // Read the next integer from the screen 
	        B= scan.nextInt();
	        check(k,A,B);
	        } int k; k int A; A int B; B Scanner scan = new Scanner(System.in); scan new Scanner(System.in) k= scan.nextInt() k scan.nextInt() scan.nextInt scan A = scan.nextInt() A scan.nextInt() scan.nextInt scan B= scan.nextInt() B scan.nextInt() scan.nextInt scan check(k,A,B) check k A B String[] args args public static void check(int k,int A,int B)
	{
		int l=0;
		for(int i=A;i<=B;i++)
		{
			if(i%k==0)
			{
			l=1	;
			}
		}
		
		if(l==1)
		{
			System.out.print("OK");
		}
		else 
		{
			System.out.print("NG");	
		}	
	} check {
		int l=0;
		for(int i=A;i<=B;i++)
		{
			if(i%k==0)
			{
			l=1	;
			}
		}
		
		if(l==1)
		{
			System.out.print("OK");
		}
		else 
		{
			System.out.print("NG");	
		}	
	} int l=0; l 0 for(int i=A;i<=B;i++)
		{
			if(i%k==0)
			{
			l=1	;
			}
		} int i=A; int i=A; i A i<=B i B i++ i++ i {
			if(i%k==0)
			{
			l=1	;
			}
		} {
			if(i%k==0)
			{
			l=1	;
			}
		} if(i%k==0)
			{
			l=1	;
			} i%k==0 i%k i k 0 {
			l=1	;
			} l=1 l 1 if(l==1)
		{
			System.out.print("OK");
		}
		else 
		{
			System.out.print("NG");	
		} l==1 l 1 {
			System.out.print("OK");
		} System.out.print("OK") System.out.print System.out System System.out "OK" {
			System.out.print("NG");	
		} System.out.print("NG") System.out.print System.out System System.out "NG" int k k int A A int B B public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		int k;
		int A;
		int B;
		  Scanner scan = new Scanner(System.in);
		  
		 // Read the next integer from the screen 
		 	k= scan.nextInt(); 
		 	
	        
	        // Read the next integer from the screen 
	        A = scan.nextInt(); 
	        
	       
	        
	        // Read the next integer from the screen 
	        B= scan.nextInt();
	        check(k,A,B);
	        }
	public static void check(int k,int A,int B)
	{
		int l=0;
		for(int i=A;i<=B;i++)
		{
			if(i%k==0)
			{
			l=1	;
			}
		}
		
		if(l==1)
		{
			System.out.print("OK");
		}
		else 
		{
			System.out.print("NG");	
		}	
	}
} public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		int k;
		int A;
		int B;
		  Scanner scan = new Scanner(System.in);
		  
		 // Read the next integer from the screen 
		 	k= scan.nextInt(); 
		 	
	        
	        // Read the next integer from the screen 
	        A = scan.nextInt(); 
	        
	       
	        
	        // Read the next integer from the screen 
	        B= scan.nextInt();
	        check(k,A,B);
	        }
	public static void check(int k,int A,int B)
	{
		int l=0;
		for(int i=A;i<=B;i++)
		{
			if(i%k==0)
			{
			l=1	;
			}
		}
		
		if(l==1)
		{
			System.out.print("OK");
		}
		else 
		{
			System.out.print("NG");	
		}	
	}
} Main
import java.util.*;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		int k;
		int A;
		int B;
		  Scanner scan = new Scanner(System.in);
		  
		 // Read the next integer from the screen 
		 	k= scan.nextInt(); 
		 	
	        
	        // Read the next integer from the screen 
	        A = scan.nextInt(); 
	        
	       
	        
	        // Read the next integer from the screen 
	        B= scan.nextInt();
	        check(k,A,B);
	        }
	public static void check(int k,int A,int B)
	{
		int l=0;
		for(int i=A;i<=B;i++)
		{
			if(i%k==0)
			{
			l=1	;
			}
		}
		
		if(l==1)
		{
			System.out.print("OK");
		}
		else 
		{
			System.out.print("NG");	
		}	
	}
}
