#include<iostream>
#include<cstring>
using namespace std;
int big(int a,int b){
	if(a>=b){
		return a;
	}else{
		return b;
	}
}
int main(){
	char a[99999]={},b[99999]={};
	cin>>a>>b;
	int a2=strlen(a),b2=strlen(b),o=0,e,f,y=0,n1,n2;
	int aa[big(a2,b2)]={};
	if(a2<b2 ||(a2==b2 && strcmp(a,b)==-1)){
		swap(a,b);
		swap(a2,b2);
		cout<<'-';
	}
	for(int c=0;c<big(a2,b2);c++){
		e=(int(a[a2-c-1])<10?int(a[a2-c-1]):int(a[a2-c-1]-48));
		f=(int(b[b2-c-1])<10?int(b[b2-c-1]):int(b[b2-c-1]-48));
		aa[big(a2,b2)-c-1]+=(e-f);
		if(aa[big(a2,b2)-c-1]<0){
			aa[big(a2,b2)-c-1]+=10;
			aa[big(a2,b2)-c-2]-=1;
		}
	}
	for(int d=0;d<big(a2,b2);d++){
		if(aa[d]>0 || o>0){
			o++;
			cout<<aa[d];
		}
	}
	if(o==0){
		cout<<0;
	}
}
'''