大整數的方法返回的不是一個字串，而是this val 

如果出現連續大整數處理，就需要把它變成字串

方法參考下面程式碼：

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

public class Wn {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
//        System.out.println(n);
 

        
        BigInteger fif = new BigInteger("0");
        BigInteger min = new BigInteger("0");
        
        for (int i = 0; i < n; i++) {
            String qq = sc.nextInt()+"";
            String vv = sc.nextInt()+"";
            
            BigInteger q = new BigInteger(qq);
            BigInteger v 
 
= new BigInteger(vv);
            BigInteger tt = new BigInteger(q.subtract(v)+"");
            fif = new BigInteger(fif.add(tt)+"");
        }
        
        if(fif.compareTo(min)==-1) {
            System.out.println("A company will go bankruptcy!");
        }else {
            System.out.println(
 
"No company will go bankruptcy!");
        }
    }
}