RT

#include<iostream>
#include<cstring>
using namespace std;
int main(){
	char s1[1001] , s2[1001];
	int n1[1001] = {} , n2[1001] = {} , n3[1001] = {};
	cin >> s1 >> s2;
	int l1 = strlen(s1) , l2 = strlen(s2);
	if (l2 > l1 || l1 == l2 && strcmp(s1 ,s2) < 0){
		swap(s1 , s2);
		swap(l1 , l2); 
		cout << "-";
	}
	for (int i = 0 ; i < l1 ; i ++){
		n1[l1 - 1 - i] = s1[i] - '0';
	}
	for (int j = 0 ; j < l2 ; j ++){
		n2[l2 - 1 - j] = s2[j] - '0';
	}
	int maxlen = l1 , l3 = 0;
	while (l3 < maxlen){
		if (n1[l3] >= n2[l3]){
			n3[l3] = n1[l3] - n2[l3];
		}
		else{
			n1[l3] += 10;
			n1[l3 + 1] --;
			n3[l3] = n1[l3] - n2[l3];
		}
		l3 ++;
	}
	l3 = maxlen - 1;
	while (n3[l3] == 0 && l3 > 0){
		l3 --;
	}
	for (int k = l3 ; k >= 0 ; k --){
		cout << n3[k];
	}
	return 0;
}