Substring Extraction

Background

Congcong is currently learning about string operations. He encountered a problem that requires extracting a substring of a specific length from a given string.

Problem Description

Given a string and an index, return a string of length $2$ starting at the given index. If the index is too big or too small to define a string of length $2$, use the first $2$ characters of the string. The string length will be at least $2$.

Input Format

The input consists of two lines.

The first line contains a string $S$. The second line contains an integer $idx$, representing the starting index.

Output Format

Output a string, which is the extracted substring.

Sample

java"

"ja"

java"

"va"

java"

"ja"

Sample Explanation

• For Sample 1, assuming the input string is "java" and the index is $0$. The substring of length $2$ starting at index $0$ is "ja".
• For Sample 2, assuming the input string is "java" and the index is $2$. The substring of length $2$ starting at index $2$ is "va".
• For Sample 3, assuming the input string is "java" and the index is $-1$ or $3$. Since the index is too small or too large to define a substring of length $2$, the first $2$ characters of the string, "ja\