const rl=require("readline").createInterface(process.stdin,process.stdout);

rl.question("",n=>{
	for(var i=1;i<=n;i=0|i+1){
		console.log("a"+(""+i)
		.replace("0","y")
		.replace("1","o")
		.replace("2","s")
		.replace("3","g")
		.replace("4","p")
		.replace("5","e")
		.replace("6","c")
		.replace("7","z")
		.replace("8","a")
		.replace("9","f")
		+(i==n? "n": "a"));
	}
	process.exit();
});