CodeFroces 805B 3-palindrome

3-palindrome time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output

In the beginning of the new year Keivan decided to reverse his name. He doesn't like palindromes, so he changed Naviek to Navick.

He is too selfish, so for a given n he wants to obtain a string of n characters, each of which is either 'a', 'b' or 'c', with no palindromes of length 3 appearing in the string as a substring. For example, the strings "abc" and "abca" suit him, while the string "aba" doesn't. He also want the number of letters 'c' in his string to be as little as possible.

Input

The first line contains single integer n (1 ≤ n ≤ 2·105) — the length of the string.

Output

Print the string that satisfies all the constraints.

If there are multiple answers, print any of them.

Examples input 2 output aa input 3 output bba Note

A palindrome is a sequence of characters which reads the same backward and forward.

题目大意：给出字符串长度n，你可以用a b c三个字符构造名字。要求，c尽量少用，且每三个连续的字符不能构成回文串。

我自己手写了一下，发现abb aabb aabb...就会一直不产生回文，交一发就A了。

代码如下：

#include<bits/stdc++.h> using namespace std; int main() { int n; char a[10] = "abb", b[10] = "aabb"; cin >> n; if(n > 3) { printf("abb"); n -= 3; for(int i = 0; i < n; i++) cout << b[i % 4]; cout << endl; } else { for(int i = 0; i < n; i++) cout << a[i]; cout << endl; } return 0; }