#include<bits/stdc++.h>
using namespace std;
string x,y;
int a[100000000],b[100000000],c[100000000],lx,ly,lc,i,t=0,k;
bool z;
int main(){
	cin>>x>>y;
	lx=x.size();
	ly=y.size();
	if(ly>lx||ly==lx&&y>x){
		swap(x,y);
		i=lx;
		lx=ly;
		ly=i;
		z=true;
	}
	for(i=1;i<=lx;i++) a[i]=x[lx-i]-'0';
    for(i=1;i<=ly;i++) b[i]=y[ly-i]-'0';
	lc=max(lx,ly);
	    for(i=1;i<=lc+1;i++){
		k=a[i]-b[i]-t;
		if(k<0){
			t=1;
			k+=10;
		}
		c[i]=k;
	}
	while(c[lc] == 0)lc --;
	if(z==true) cout<<"-";
	for(i=lc;i>0;i--) cout<<c[i];
	if(lc<1) cout<<0;
}