Problem:
Score: 100 points

Problem Statement

Takahashi the Jumbo will practice golf.

His objective is to get a carry distance that is a multiple of K, while he can only make a carry distance of between A and B (inclusive).

If he can achieve the objective, print OK; if he cannot, print NG.

Constraints

All values in input are integers.

1 \leq A \leq B \leq 1000

1 \leq K \leq 1000

Input

Input is given from Standard Input in the following format:

K
A B

Output

If he can achieve the objective, print OK; if he cannot, print NG.

Sample Input 1

7
500 600

Sample Output 1

OK

Among the multiples of 7, for example, 567 lies between 500 and 600.

Sample Input 2

4
5 7

Sample Output 2

NG

No multiple of 4 lies between 5 and 7.

Sample Input 3

1
11 11

Sample Output 3

OK

Solution in C# (Mono-csc 3.5.0) (judge verdict: Accepted)

namespace Test
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;

    public class Test
    {
        public static void Main(string[] args)
        {
            var t = new Test();
            var n = t.ReadInputOneLine();
            var input = t.ParseIntList(t.ReadInput());
            bool ans = false;
            for(var i = input[0]; i<=input[1]; i++)
            {
                if(i % n == 0)
                {
                    ans = true;
                    break;
                }
            }
            if (ans)
            {
                Console.WriteLine("OK");
            }
            else
            {
                Console.WriteLine("NG");
            }
        }


        public int ReadInputOneLine()
        {
            return int.Parse(Console.ReadLine());
        }

        public string[] ReadInput()
        {
            return Console.ReadLine().Split(' ');
        }

        public List<int> ParseIntList(string[] x)
        {
            var convertedList = new List<int>(x.Length);
            for (var i = 0; i < x.Length; i++)
            {
                convertedList.Add(int.Parse(x[i]));
            }

            return convertedList;
        }


        public List<double> ParseDoubleList(string[] x)
        {
            var convertedList = new List<double>(x.Length);
            for (var i = 0; i < x.Length; i++)
            {
                convertedList.Add(double.Parse(x[i]));
            }

            return convertedList;
        }

        public List<long> ParseLongList(string[] x)
        {
            var convertedList = new List<long>(x.Length);
            for (var i = 0; i < x.Length; i++)
            {
                convertedList.Add(long.Parse(x[i]));
            }

            return convertedList;
        }

        public int CountContainWords(string source, string word)
        {
            var count = 0;
            var loopCount = source.Length - (word.Length - 1);
            for (var i = 0; i < loopCount; i++)
            {
                if (source.Substring(i, word.Length) == word)
                {
                    count++;
                }
            }
            return count;
        }
    }
}