103332: [Atcoder]ABC333 C - Repunit Trio

Problem Statement

A repunit is an integer whose digits are all $1$ in decimal representation. The repunits in ascending order are $1, 11, 111, \ldots$.

Find the $N$-th smallest integer that can be expressed as the sum of exactly three repunits.

Constraints

• $N$ is an integer between $1$ and $333$, inclusive.

Input

The input is given from Standard Input in the following format:

$N$

Output

Print the answer.

Sample Input 1

5

Sample Output 1

113

The integers that can be expressed as the sum of exactly three repunits are $3, 13, 23, 33, 113, \ldots$ in ascending order. For example, $113$ can be expressed as $113 = 1 + 1 + 111$.

Note that the three repunits do not have to be distinct.

Sample Input 2

19

Sample Output 2

2333

Sample Input 3

333

Sample Output 3

112222222233

问题描述

回文数是一个其十进制表示中所有数字都为1的整数。从小到大的回文数依次为1, 11, 111, ...。

找出能够表示为恰好三个回文数之和的第N小的整数。

限制条件

• N是一个介于1和333之间的整数。

输入

输入从标准输入中给出，格式如下：

$N$

输出

输出答案。

样例输入1

5

样例输出1

113

从小到大，能够表示为恰好三个回文数之和的整数为3, 13, 23, 33, 113, ...。例如，113可以表示为113 = 1 + 1 + 111。

注意，这三个回文数不必不同。

样例输入2

19

样例输出2

2333

样例输入3

333

样例输出3

112222222233