Problem stotement

You are given a binary string $\text{'}$S$\text{'},$ i$.$e$.\text{'}$Stj$\text{'}\text{'}$is either $\text{'}0\text{'}$ or $\text{'}11.$ For this task, you are

asked to retum the sum of the length of all the substring which contains an odd

number of $1$ :

For Exomple:

$S=010101$

Here, the substrings with an odd number of $"19$s are $"1","10","10101","01",$

$"010","1","10","01",$ and $"1".$

Therefore, we retum $19$ for the given example.

Detoiled explongition $($Input$/$output format, Notes, Images$)$

Constuints:

$1>$ Slength $>1015$

$0^{\text{'}}>S[]>11$

ime Limit $1$ second

Sample Input $1$:

$100101$

Sample Outout $1$:

Sample Input is

$100101$

Sample output $1$:

$30$

Explanation :

All the substrings with odd numbers of $1\text{'}$s are $"1","10",$

$"100","100101","601","0010","01","010","1","10","01"$

and $"1".$ Therefore the sum of length will be

$1+2+3+6+3+4+2+3+1+2+2+1=30$

Hence we return $30.$

Sample Input $2$:

$101010$

Sample output $2$:$30$