【题解】【上海】【最后一击】

#include <iostream>
using namespace std;
long long n, a, b, x = 1, y = 1, cont = 0, sum = 0;
bool q = false, g = false, d = false;
int main()
{
	cin.tie(0);
	cin >> n >> a >> b;
	while(sum < n)
	{
		if (a * y > b * x)
			sum++, x++, q = true, g = false, d = false;
		else if (a * y == b * x)
			sum += 4, x++, y++, q = false, g = false, d = true;
		else
			sum++, y++, q = false, g = true, d = false;
	}
	if (q == true)	
		cout << "A";
	else if (g == true)	
		cout << "B";
	else if (d == true)	
		cout << "C";
	return 0;
}