#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
using namespace std;
typedef long long int ll;
#define dame { puts("-1"); return 0;}
#define yn {puts("Yes");}else{puts("No");}


int main() {
    int n;
    cin >> n;

    int ans = n*n*n;

    cout << ans << endl;
    return 0;
}
 
 


#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;++i)
typedef long long int ll;
typedef pair<int,int> P;
const int INF = 1e9+7;

int main(){
    int r;
    cin >> r;
    if(r<1200){
        cout << "ABC";
    }else if(1200<=r&&r<2800){
        cout << "ARC";
    }else{
        cout << "AGC";
    }
}