#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <map>
#include <stack>
#include <cmath>
#include <queue>
#include <numeric>


int main()
{
	int height[3];

	for (size_t i = 0; i < 3; i++)
	{
		std::cin >> height[i];
	}

	char name[3][2] = { "A", "B", "C" };
	int pos[3] = { 0, 1, 2 };

	if (height[0] < height[1]) {
		std::swap(height[0], height[1]);
		std::swap(pos[0], pos[1]);
	}

	if (height[1] < height[2]) {
		std::swap(height[1], height[2]);
		std::swap(pos[1], pos[2]);
	}

	if (height[0] < height[1]) {
		std::swap(height[0], height[1]);
		std::swap(pos[0], pos[1]);
	}

	for (size_t i = 0; i < 3; i++)
	{
		std::cout << name[pos[i]] << std::endl;
	}

	return 0;
}