Problem
Professor Mac Gonagall was an excellent Quidditch player . But in the 7th year, during a game against Slytherin, after a foul by the enemy, she fell off the broom, broke several ribs, received a concussion, and never returned to the sport. But it was then that her legendary sense of athletic rivalry with this house, which we see in the books, was born - no one is more zealous against Slytherin than the head of the Gryffindor house.
In matches between the House of Gryffindor and Slytherin, Severus Snape could quietly change the score. That's why Professor McGonaggal always recorded every goal she scored.
For example, she could write something like this:
1:0
1:1
1:2
2:2
2:3
After that, she added up all written numbers:
1+0+1+1+1+2+2+2+2+3 = 15.
According to the sum obtained by Professor McGonaggal, determine how many goals were scored in the match.
Input
One natural number is entered, not exceeding 1000 – amount received by Professor Mac Gonaggal.
Imprint
Print one number – total number of goals scored.
Examples
| # |
Input |
Output |
| 1 |
3 |
2 |
| 2 |
1 |
1 |