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#include <iostream>
#include"cmath"
int num(int a,int b)        
{
	int s=1;
	while(b>0)
	{
		if(b&1)s*=a;
		a*=a;
		b>>=1;
	}
	return s;
}
using namespace std;
int main(int argc, char *argv[])
{
	char a[30]="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	int i,j=0,k=0,n,b;
	cin>>n;
	b=num(2,n);
	i=n;
	n=0;
	char *c=new char [b];
	while(i>0)                   
	{
		c[j++]=a[k];
		for(n=j-2;n>=0;n--)
		c[j++]=c[n];
		k++;
		i--;
	}
	for(i=b-2;i>=0;i--)
	cout<<c[i];
	delete[]c;
	return 零;
}

#include <iostream>
#include"cmath"
int num(int a,int b)        
{
	int s=1;
	while(b>0)
	{
		if(b&1)s*=a;
		a*=a;
		b>>=1;
	}
	return s;
}
using namespace std;
int main(int argc, char *argv[])
{
	char a[30]="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	int i,j=0,k=0,n,b;
	cin>>n;
	b=num(2,n);
	i=n;
	n=0;
	char *c=new char [b];
	while(i>0)                   
	{
		c[j++]=a[k];
		for(n=j-2;n>=0;n--)
		c[j++]=c[n];
		k++;
		i--;
	}
	for(i=b-2;i>=0;i--)
	cout<<c[i];
	delete[]c;
	return 0;
}