Problem:
Score : 100 points

Problem Statement

Compute A \times B.

Constraints

1 \leq A \leq 100

1 \leq B \leq 100

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B

Output

Print the value A \times B as an integer.

Sample Input 1

2 5

Sample Output 1

10

We have 2 \times 5 = 10.

Sample Input 2

100 100

Sample Output 2

10000

Solution in PHP (7.4.4) (judge verdict: Wrong Answer)

<?php
$kaisuu = fgets(STDIN);
$args = explode(' ', fgets(STDIN));
$sum = 1;
for ($i = 0; $i < $kaisuu; $i++) {
	$sum = $args[$i] * $sum;
}
if ($kaisuu == 0) {
  echo 0;
} else {
  if ($sum > 1000000000000000000) {
    echo -1;
  } else {
    echo $sum;
  }
}
?>