# ZeroJudge - a863: 3. Happy Numbers
### 題目連結：https://zerojudge.tw/ShowProblem?problemid=a863
###### tags: `ZeroJudge` `數學` `數論`

#include <iostream>
using namespace std;

int main() {
	cin.sync_with_stdio(false); cin.tie(nullptr);
	int number, buffer;
	while (cin >> number) {
		cout << number;
		while (number != 1 && number != 4) {
			buffer = 0;
			while (number) {
				buffer += (number % 10) * (number % 10);
				number /= 10;
			}
			number = buffer;
		}
		cout << (number == 1 ? " is a happy number\n" : " is an unhappy number\n");
	}
}