#include <bits/stdc++.h>
using namespace std;

const int MAX = 1500;

int main() {
	string a, b;
	int na[MAX] = {0}, nb[MAX] = {0};
	int c[MAX] = {0};
	
	cin >> a >> b;
	
	reverse(a.begin(), a.end());
	reverse(b.begin(), b.end());
	
	int la = a.length();
	int lb = b.length();
	
	for (int i = 0; i < la; i++) {
		na[i] = a[i] - '0';
	}
	
	for (int i = 0; i < lb; i++) {
		nb[i] = b[i] - '0';
	}
	
	int times = max(la, lb);
	

	bool bos = false;
	if (la < lb || (la == lb && a < b)) {
		swap(a, b);
		swap(na, nb);
		swap(la, lb);
		bos = true;
	}
	
	int borrow = 0;
	for (int i = 0; i < times; i++) {
		int mi = na[i] - nb[i] - borrow;
		if (mi < 0) {
			mi += 10;
			borrow = 1;
		} else {
			borrow = 0;
		}
		c[i] = mi;
	}
	

	while (times > 1 && c[times - 1] == 0) {
		times--;
	}
	
	if (bos) {
		cout << '-';
	}
	for (int i = times - 1; i >= 0; i--) {
		cout << c[i];
	}
	
	return 0;
}