shui

#include<bits/stdc++.h> 
using namespace std;
string s1,s2;
int a[100010],b[10010],ans[10020];
int len1,len2,f;
int main(){
	cin>>s1>>s2;
	len1=s1.size();
	len2=s2.size();
	if(len2>len1){
		f=-1;
		cout<<"-";
        swap(len1,len2);
        swap(s1,s2);
	}	else if(len2==len1&&s2>s1){
			cout<<"-";
        swap(len1,len2);
			swap(s1,s2);
		}
	for(int i=1,j=len1-1;j>=0;i++,j--){
		a[i]=s1[j]-'0';
	}
	for(int i=1,j=len2-1;j>=0;i++,j--){
		b[i]=s2[j]-'0';
	}
	int c=0;
	for(int i=1;i<=10010;i++){
		ans[i]=a[i]-b[i]+c;
		if(ans[i]<0){
			c=-1;
			ans[i]+=10;
		}else{
            c=0;
        }
        
	}
	int i=10009;
	while(i>=1&&ans[i]==0) i--;
	if(i==0){
		cout<<0<<endl;
	}else{
		while(i>=1){
			cout<<ans[i];
			i--;
		}
	}
	return 0;
}