#10872

#include <iostream>
using namespace std;

int fac(int n)
{
	if (n <= 1)
		return 1;

	return n = n * fac(n - 1);
}

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

	cout << fac(N);

	return 0;
}

#10870

#include <iostream>
using namespace std;

int fib(int n)
{
	if (n == 0)
		return 0;
	else if (n == 1)
		return 1;
	else
		return fib(n - 2) + fib(n - 1);
}

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

	cout << fib(N);
	return 0;
}

#2447

#include <iostream>
using namespace std;

void star(int i, int j, int n)
{
	if ((i % 3) == 1 && (j % 3) == 1)
	{
		cout << " ";
	}
	else if (n == 0) //n이 3의 제곱근이므로 3으로 나눠질때만 *찍기
	{
		cout << "*";
	}
	else
	{
		star(i / 3, j / 3, n/3);
	}

}

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

	for (int i = 0; i < N; i++)
	{
		for (int j = 0; j < N; j++)
			star(i, j, N);
		cout << "\n";
	}
	return 0;
}

#11729

#include <iostream>
#include <cmath>
using namespace std;

void hanoi(int n, int A, int B, int C)
{
	if (n == 1)
	{
		cout << A << " " << C << "\n";
	}
	else
	{
		hanoi(n - 1, A, C, B);
		cout << A << " " << C << "\n";
		hanoi(n - 1, B, A, C);
	}
}

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

	cout << (int)pow(2, N) -1 << "\n";
	hanoi(N, 1, 2, 3);
}