#include <stdio.h>
 
int main(void) {
	char password[9] = {0};
	int keysize = 4;
	for (;;) {
	    // get next password value
	    // we do it by adding 1 in 26-al system
	    int level = 0; // current level, starts at 0
	    while (level < keysize) {
	        if (password[level] == 0) {
	            password[level] = 'a';
	            break;
	        }
	        if (password[level] >= 'a' && password[level] < 'c') {
	            password[level]++;
	            break;
	        }
	        if (password[level] == 'c') {
	            password[level] = 'a';
	            level++;
	        }
	    }
	    if (level >= keysize)
	        break; // we have checked all passwords!
	    // check if password matches:
	    //if (check_password(password)) {
	    //    printf("Hooray! Password found: %s\n", password);
	    //    break;
	    //}
	    printf("%s ", password);
	}
	return 0;
}
 

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