十余行代码解决问题
import java.math.BigInteger;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
BigInteger a = sc.nextBigInteger();
BigInteger b = sc.nextBigInteger();
BigInteger cnt = a.subtract(b);
System.out.println(cnt);
}
}