Double Characters

Given a string S, write a program to produce a new string in which every character in S is repeated twice. For instance, if S = "hello", then the output should be "hheelllloo".

This problem requires you to process an input string and output a modified version where each alphabetic character is duplicated. The program should properly handle both uppercase and lowercase letters, preserving their original case.

In mathematical notation, if the input string is represented as \(S = s_1 s_2 \cdots s_n\), then the output string should be \(T = s_1 s_1 s_2 s_2 \cdots s_n s_n\).

inputFormat

The input consists of a single line containing a non-empty string S composed of alphabet characters. You can assume that \(1 \leq |S| \leq 10^5\).

outputFormat

Output the modified string where every character of the input string is repeated twice.

hello

hheelllloo