A.cpp

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;

#define rep(i, a, b) for (auto i = (a); i < (b); ++i)
#define per(i, a, b) for (auto i = (b); i-- > (a); )
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) int((x).size())

template<class T> bool uin(T& a, const T& b) { return a > b ? a = b, true : false; }
template<class T> bool uax(T& a, const T& b) { return a < b ? a = b, true : false; }

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

string pad(int x) {
	string ret = to_string(x);
	reverse(all(ret));
	ret += string(max(0, 3 - sz(ret)), '0');
	reverse(all(ret));
	return ret;
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n; cin >> n;
	cout << "AGC" << pad(n + (n >= 42)) << '\n';
}