//高精度减法运算 
#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

char s1[300], s2[300], s3[300];
int a[300], b[300];

int main()
{
	int la, lb, m=0;
	cin >> s1 >> s2;
	la = strlen(s1);
	lb = strlen(s2);
	if(strcmp(s1, s2) == 0)
	{
		cout << 0;
		return 0;
	}
	if(la<lb || la==lb && strcmp(s1, s2)<0 )
	{
		cout << "-";
		strcpy(s3, s1);
		strcpy(s1, s2);
		strcpy(s2, s3);
	}
	la = strlen(s1);
	lb = strlen(s2);
	for(int i=1;i<=la;i++)
		a[i] = s1[la-i] - 48;
	for(int i=1;i<=lb;i++)
		b[i] = s2[lb-i] - 48;
	for(int i=1;i<=la;i++)
	{
		if(a[i] < b[i])
		{
			a[i+1]--;
			a[i] += 10;
		}
		a[i] -= b[i];
	}
	
	while(a[la] == 0 && la>1)
		la--;
	for(int i=la;i>=1;i--)
		cout << a[i];
	cout << endl;
	
	return 0;
}