http://acm.hdu.edu.cn/showproblem.php?pid=1108 java BIgInteger gcd

]import java.util.*;
import java.io.*;
import java.math.*;
public class Main1108 {
public static void main(String[] args){
int a, b;
Scanner cin = new Scanner(new BufferedInputStream(System.in));
while( cin.hasNext()){
a = cin.nextInt();
b = cin.nextInt();
BigInteger aa = BigInteger.valueOf(a);
BigInteger bb = BigInteger.valueOf(b);
BigInteger cc = aa.gcd(bb);
System.out.println(aa.multiply(bb).divide(cc));
}
}
}