import java.util.*;

public class Main { public static void main(String[] args) { Scanner console = new Scanner(System.in); int m = console.nextInt(); int n = console.nextInt(); //计算最小公倍数 int result = getCM(m, n); System.out.println(result); }

public static int getCM(int m, int n){

    //write your code here......
    int max=Math.max(m,n);
    for(int i=max;i<=m*n;i++){
        if(i%m==0&i%n==0){
            return i;
        }
    }
    return -1;
}

}