Family's earning childrenFamily's earning children

In the Michaelson family, all the children start earning at the age of $20.$

You are given the table which has a list of siblings and their age

differences. Ranks are given in increasing order to all siblings from

youngest to oidest & the youngest sibling has rank $1.$ The age of the

youngest sibling is $15.$ The table is siblings.

Task

If the age difference between a sibling with its direct younger sibling is

given, find the number of siblings who earn.

Table description

Input format

Table: siblings

Output format

Sample input

Table: siblings

Sample output

In the Michaelson family, all the children start earning at the age of $20.$

You are given the rable which has a list of siblings and their age

differences. Ranks are given in increasing order to all siblings from

youngest to oidest & the youngest sibling has rank $1.$ The age of the

youngest sibling is $15.$ The table is siblings.

Task

If the age difference between a sibling with its direct younger sibling is

given, find the number of siblings who earn.

Table description

Input format

Table: siblings

Output format

Sample input

Table: siblings

Sample output