# Finding Binary In Decimal

Easy
0/40
Average time to solve is 15m
Contributed by

## Problem statement

Given an integer ‘N’, the task is to find the number of integers between 1 to N whose decimal number representation contains only 0s and 1s.

For example, 1011 , 11, 100 are all valid integers since they consist of 1s and 0s only, however 210, 3401 are not valid integers.

Note :
``````You don’t need to print anything. It has already been taken care of. Just implement the given function.
``````
Detailed explanation ( Input/output format, Notes, Images )
Constraints :
``````1 <= T <= 10^4
1 <= N <= 10^9

Time Limit: 1sec
``````

#### Sample input 1 :

``````2
10
21
``````

#### Sample output 1 :

``````2
3
``````

#### Explanation for sample input 1 :

``````In first case, there are only 2 numbers between 1 to 10 that contain only 1s or 0s i.e (1,10)In second case, there are only 3 numbers  containing only 0s and 1s i.e (1,10,11)
``````

#### Sample input 2 :

``````3
250
1505
3010
``````

#### Sample output 2 :

``````7
15
15
``````
Console