PythonEasyStrings10 min

Check whether a string is a palindrome

Compare characters exactly, including spaces and letter case. The empty string is a palindrome. Interviewers use this problem to assess move two pointers inward and stop on the first mismatch.

Input

One ASCII line.

Output

Print true or false in lowercase.

Constraints

0 <= length <= 100000.

Example

Input

racecar

Output

true

Example 2 input

a a

Output

true

Spaces participate in the comparison.

Public test cases (2)

Input
```
racecar
```
Expected output
```
true
```
Input
```
Python
```
Expected output
```
false
```

Hints (2)

Identify the state needed to avoid repeated work.
Move two pointers inward and stop on the first mismatch.

Target complexity: time O(n) · space O(1)

Your solution

import sys


def solve_palindrome_string(s):
    # your code
    return False


if __name__ == "__main__":
    data = sys.stdin.read()
    s = data.split("\n", 1)[0]
    result = solve_palindrome_string(s)
    print("true" if result else "false")

Standard input

Checking runner availability…

Reference solution

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All Python programs

Check whether a string is a palindrome

Input

Output

Constraints

Example

Public test cases (2)

Your solution

Reference solution

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