Given a string
s, you are asked to calculate the longest substring of
swith no duplicate letters. The program should print the first occurring one in case of multiple such strings.
The only line of the input contains a string
s(1 ≤ |s| ≤ ).
scan contain Latin letters, ASCII symbols (~,#$-=_|\/+%^&*()’”.!@), spaces, and tabs.
The program should print the longest substring of
swith all unique letters.