#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<string>
#include<cstdio>
using namespace std;
string s1,s2,s3;
int a[50000],b[50000];
int main()
{
    cin>>s1>>s2;
    if(s1<s2)
    {
    	s3=s1;
    	s1=s2;
    	s2=s3;
    	cout<<"-";
	}
    a[0]=s1.size();b[0]=s2.size();
    for(int i=1;i<=a[0];++i)
        a[i]=s1[a[0]-i]-'0';
    for(int i=1;i<=b[0];++i)
        b[i]=s2[b[0]-i]-'0'; 
	int n=max(a[0],b[0]);
	for(int i=1;i<=n;++i)
	{
		if(a[i]<b[i])
		{
		    --a[i+1];
			a[i]+=10;
		}
		a[i]=a[i]-b[i];
	}
	while(a[n]==0&&n>1) n--;
	for(int i=n;i>0;--i)
	    cout<<a[i];
	cout<<endl;
	return 0;
}