大数相乘和大数相加。

/*

*大数相乘 求n的阶乘。

*/

import java.math.BigInteger;
import java.util.Scanner;

public class BigMultiply {

public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int N = sc.nextInt();
System.out.println(calcM(N));
}

public static String calcM(int n) {
BigInteger one = new BigInteger(Integer.toString(1));

for (int i = 1; i <= n; i++) {
one = one.multiply(new BigInteger(Integer.toString(i)));// 大数据的加减乘除用的是add、subtract、multiply、divide，remainder。
}
return one.toString();
}

}

/*

大数相加

*/

import java.math.BigInteger;
import java.util.Scanner;

public class BigPlus {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String arg1 = sc.nextLine();
String arg2 = sc.nextLine();
BigPlus big=new BigPlus();
System.out.println(big.plusBigNum(arg1, arg2));
}

public String plusBigNum(String arg1, String arg2) {
BigInteger big1 = new BigInteger(arg1);
BigInteger big2 = new BigInteger(arg2);// 将输入字符串转化为大数对象。
return big1.add(big2).toString();//toString注意。
}

}