#include <iostream>
using namespace std;
//120, 84, 25, 1, 15, 17, 42, 21, 9, 12, 3, 49, 8, 29, 82, 31, 87, 118, 88, 92, 93 
int main() {
	int i = 0, j= 0, k = 0, l = 0;
	int a= 120;
	int b = 84;
	int c = 25;
	int d = 1;
	
	cout<<(4^1)<<"\n";
	for ( i = 0; i <= 127; i++)
	{
		for(j = 0; j<= 127; j++)
		{
			for(k = 0; k<= 127; k++)
			{
				for(l = 0; l <= 127; l++ )
				{
					if(97 <= (a^i) && (a^i) <= 122)
					{
						if(97 <= (b^j) &&(b^j) <= 122)
						{
							if(97 <= (c^k) && (c^k) <= 122)
							{
								if(97 <= (d^l) && (d^l) <= 122)
								{
									cout<<(char)(a^i);
									cout<<(char)(b^j);
									cout<<(char)(c^k);
									cout<<(char)(d^l);
									cout<<" ";
								}
							}
						}
					}
				}
			}
		}
	}
	return 0;
}