#include<bits/stdc++.h>
using namespace std;
string s1,s2;
char f='+';
int n1[250],n2[250];
int a[250],b[250],r[250];
int main()
{

	cin>>s1>>s2;
	if(s1.size()<s2.size() || (s1.size()==s2.size() && s1<s2))
	{
	    swap(s1,s2);	
	    f='-';
	}
	for(int i=0;i<s1.size();i++)
	{
		n1[i]=s1[s1.size()-1-i]-48;
	}
	for(int i=0;i<s2.size();i++)
	{
		n2[i]=s2[s2.size()-1-i]-48;
	}
	int len=s1.size();
	for(int i=0;i<len;i++)
	{
		if(n1[i]<n2[i])
		{
			n1[i+1]=n1[i+1]-1;
			n1[i]=n1[i]+10;
		}
		r[i]=n1[i]-n2[i];
	}
	int p=0;
	for(int i=len-1;i>=0;i--)
	{
		if(r[i]!='0')
		{
			p=i;
			break;
		}
	}
	for(int i=p;i>=0;i--)
	{
		cout<<r[i];
	}
	return 0;
}
/**************************************************************
	Problem: 1269
	User: chenkexin
	Language: C++
	Result: Wrong Answer
****************************************************************/