#include<bits/stdc++.h>
#define N 1000005
using namespace std;
int main(){
    string a1,b1,t;
    int a[N]={},b[N]={};
    int la,lb,lc;
    int i;
    cin>>a1>>b1;
    la=a1.size();
    lb=b1.size();
    if(la<lb||la==lb&&a1<b1){
        t=a1;
        a1=b1;
        b1=t;
        cout<<"-";
    }
    la=a1.size();
    lb=b1.size();
    for(i=0;i<la;i++){
        a[i]=a1[la-i-1]-'0';
    }
    for(i=0;i<lb;i++){
        b[i]=b1[lb-i-1]-'0';
    }
    lc=0;
    while(lc<=la||lc<=lb){
        if(a[lc]<a[lc]){
            a[lc]=a[lc]+10;
            a[lc+1]--;
        }
        a[lc]=a[lc]-b[lc];
        lc++;
    }
    while(a[lc]==0&&lc>0){
        lc--;
    }
    for(i=lc;i>=0;i--){
        cout<<a[i];
    }
	return 0;
}