Competitions

# PP1 Week 1 Contest 1

# Marathon

The running competitions was started **a** by participants, but **b** of them left the race. How many runners finished?

#### Input

Two positive integers **a** and **b** (**a**, **b** ≤ `10`

).^{18}

#### Output

Print the number of runners who finished the race.

Input example #1

12 9

Output example #1

3