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 PyPy3 (7.3.0) (judge verdict: Accepted)

#########行列読み込み ##############################################
"""
from sys import stdin
n = int(stdin.readline().rstrip())
data = [stdin.readline().rstrip().split() for _ in range(n)]
print(data)
print(*data, sep='\n')
"""
##################################################################
#########入力系####################################################
"""
s =input()
s=list(input())
a=int(input())
x,y = map(int,input().split())	
li = input().split()	
li = list(map(int,input().split()))	
li = input().split('T')	
"""
##################################################################

#########行列読み込み ##############################################
"""
from sys import stdin
n = int(stdin.readline().rstrip())
data = [stdin.readline().rstrip().split() for _ in range(n)]
print(data)
print(*data, sep='\n')
"""
##################################################################
#########入力系####################################################
"""
s =input()
s=list(input())
a=int(input())
x,y = map(int,input().split())	
li = input().split()	
li = list(map(int,input().split()))	
li = input().split('T')	
"""
##################################################################
K = int(input())
A,B = map(int,input().split())	
cnt = 0
for i in range(A,B+1):
    if i%K==0:
       cnt +=1
       break
    
if cnt>=1:
    print("OK")
else:
    print("NG")