Submit solution

Points:
5

Time limit:
1.0s

Memory limit:
64M

Author:

Problem types

Allowed languages

Ada, Assembly, Awk, Brain****, C, C#, C++, COBOL, ~~CommonLisp~~, D, Dart, F#, Forth, Fortran, Go, ~~Groovy~~, Haskell, Intercal, Java, JS, Kotlin, Lisp, Lua, ~~Nim~~, ~~ObjC~~, OCaml, ~~Octave~~, Pascal, Perl, PHP, Pike, Prolog, Python, Racket, Ruby, Rust, Scala, Scheme, Sed, Swift, TCL, Text, Turing, VB, Zig

It's and , wants to know how many different numbers less than or equal to that only consist of digits that are either or .

's birthday, and wants to give him a gift. Knowing that he loves the numbers#### Subtasks

- (20 points)
- (80 points) No additional constraints.

#### Input Specification

A single integer .

#### Output Specification

The answer to the problem, on a single line.

#### Sample Input 1

`13`

#### Sample Output 1

`2`

#### Explanation for Sample 1

The only two numbers are and .

#### Sample Input 2

`40`

#### Sample Output 2

`6`

#### Explanation for Sample 2

The only valid numbers are , , , , and .

## Comments

This comment is hidden due to too much negative feedback. Click here to view it.

You don't need to check every number. Consider the implications of the numbers only having the digits 2 and 3.