#include<bits/stdc++.h>
using namespace std;
string s1,s2;
int a[10566],b[10566],c[10599];
bool j;
int main(){
	cin>>s1>>s2;
	int len1=s1.size();
	int len2=s2.size();
	if((s1<s2&&len1==len2)||len1<len2){
		swap(s1,s2);
		j=true;
	}
	int m=max(len1,len2);
	for(int i=len1;i>0;i--)
	a[i]=s1[len1-i]-'0';
	for(int i=len2;i>0;i--)
	b[i]=s2[len2-i]-'0';
	for(int i=1;i<=m;i++){
		if(a[i]<b[i]){
			a[i+1]--;
			a[i]+=10;
		}
		c[i]=a[i]-b[i];
	}
	while(c[m]==0)
	m--;
	if(j==true)
	cout<<"-";
	for(int i=m;i>0;i--)
	cout<<c[i];	
	if(m<1) 
		cout<<"0";
	return 0;
}