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

int length = 4;
char chars[] = "abcdefghijklmnopqrstuvwxyz";

char * brute_str = new char[length + 1];

void brute(int length){

    if(length > 0)
        length--;
    
	int chlen = strlen(chars);
    
    for(int i=0;i<chlen;i++){
        brute_str[length] = chars[i];
        
        if(length == 0)
            cout << brute_str << endl;
        
        if(length > 0)
            brute(length);
    }
}

int main(){
	
	time_t start_time,end_time;
	
	brute_str[length] = '\0';	
	time(&start_time);
	brute(length);
	time(&end_time);
	cout << end_time - start_time;
	cin.clear();
	cin.get();
	return 0;
}