#include <fstream>
#include <algorithm>
#include <string>
#include <cstring>

using namespace std;

ifstream fin("sub.in");
ofstream fout("sub.out");

const int maxn = 200 + 50;
int reva[maxn];
int revb[maxn];
int ans[maxn];
//bool flag = false;

void fswap(string &x, string &y)
{
	string temp;
	
	temp = x;
	x = y;
	y = temp;
	
	return ;
}
int main()
{
	memset(reva, 0, sizeof(reva));
	memset(revb, 0, sizeof(revb));
	memset(ans, 0, sizeof(ans));
	
	string a, b;
	
	fin>>a>>b;
	
	if(a==b)
	{
		fout<<'0'<<endl;
		return 0;
	}
	else
		if(a.length()<b.length()||(a.length()==b.length())&&a<b)
		{
			fswap(a, b);
			fout<<'-';
		}
	
	int la = a.length();
	int lb = b.length();
	
	for(int i=0;i<la;i++)
		reva[la-i-1] = a[i] - '0';
	for(int i=0;i<lb;i++)
		revb[lb-i-1] = b[i] - '0';
	for(int i=0;i<la;i++)
	{
		if(reva[i]<revb[i])
		{
			reva[i+1] = reva[i+1] - 1;
			reva[i] = reva[i] + 10;
		}
		ans[i] = reva[i] - revb[i];
	}
	while(la>0&&ans[la]==0)
		if(ans[la]==0)
			la--;
	for(int i=la;i>=0;i--)
		fout<<ans[i];
	fout<<endl;
	
	fin.close();
	fout.close();
	
	return 0;
}