text: # Problem Having learned the multiplication table, Takahashi can multiply two integers between 1 and 9 (inclusive) together.He cannot do any other calculation.Given are two integers A and B.If Takahashi can calculate A \times B, print the result; if he cannot, print `-1` instead.Constraints * 1 \leq A \leq 20 * 1 \leq B \leq 20 * All values in input are integers.Input Input is given from Standard Input in the following format: A B Output If Takahashi can calculate A \times B, print the result; if he cannot, print `-1`.Examples Input 2 5 Output 10 Input 5 10 Output -1 Input 9 9 Output 81 # Solution import java.util.*; class Main{ public static void main(String[] args){ Scanner scan = new Scanner(System.in); int a = scan.nextInt(); int b = scan.nextInt(); if(a>=1&&a<=9&&b>=1&&b<=9){ System.out.println(a*b); }else{ System.out.println(-1); } } }