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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#define fast ios::sync_with_stdio(0);cin.tie(0);
using namespace std;

/*void solve(){
  int n,q;cin>>n>>q;
  unordered_map<char,int>cnt;
  string s;cin>>s;
  int ma=0;
  for(int i=0;i<s.size();i++)
  {
    cnt[s[i]]++;
    if(cnt[s[i]]>ma)ma=cnt[s[i]];
  }
    int dp[ma+1]={0};
 for(auto u:cnt)
 {
     int x=u.second;
     for(int i=1;i<=x;i++)
        dp[i]++;
 }
 for(int i=1;i<ma;i++)dp[i]+=dp[i-1];
while(q--)
{
    int c;cin>>c;
    if(c>=ma)cout<<"0"<<endl;
    else cout<<n-dp[c]<<endl;
}
return;
}*/

int main(){
    fast
 int k,a,b;cin>>k>>a>>b;
if(b/k>(a-1)/k)cout<<"OK";
else cout<<"NG";
return 0;
}