#include<bits/stdc++.h>

using namespace std;

//当a,b长度相同时,判断a是否小于b
bool judge(string a, string b){
    int i = 0, n = a.size();
    while(i < n){
        int num1 = a[i] - '0', num2 = b[i] - '0';
        if(num1 < num2) return true;
        else if(num1 == num2) i++;
        else if(num1 > num2) return false;

    }
    return false;
}

int main(){
    string a, b;
    cin>>a>>b;
    bool flag = 0;
    //使a大于等于b
    if(a.size() < b.size() || (a.size() == b.size() && judge(a, b))){
        string temp = a;
        a = b;
        b = temp;
        flag = 1;
    }
    int n = a.size(), m = b.size();
    for(int i = 0; i < n-m; i++){
        b = " " + b;
    }
    for(int i = n-1, carry = 0; i >= 0; i--){
        int num1 = (a[i] != ' ') ? a[i] - '0' : 0;
        int num2 = (b[i] != ' ') ? b[i] - '0' : 0;
        int num = num1 - num2 - carry;
        a[i] = (num + 10) % 10 + '0';
        carry = num < 0 ? 1 : 0;
    }
    while(a.size() > 1 && a[0] == '0')  a.erase(0, 1);
    if(flag)    a = "-" + a;
    cout<<a<<endl;
    return 0;
}