#include <algorithm>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <vector>
#define int long long
#define endl '\n'
using namespace std;

bool operator>=(vector<int> &A, vector<int> &B)
{
    if (A.size() != B.size())
    {
        return A.size() > B.size();
    }
    for (int i = A.size() - 1; i >= 0; i--)
    {
        if (A[i] != B[i])
        {
            return A[i] > B[i];
        }
    }
    return true;
}

vector<int> operator-(vector<int> &A, vector<int> &B)
{
    vector<int> C;
    int t = 0;
    for (int i = 0; i < A.size(); i++)
    {
        t = A[i] - t;
        if (i < B.size())
        {
            t -= B[i];
        }
        C.push_back((t + 10) % 10);
        if (t < 0)
        {
            t = 1;
        }
        else
        {
            t = 0;
        }
    }
    while (C.size() > 1 && C.back() == 0)
    {
        C.pop_back();
    }
    return C;
}

signed main(void)
{
    std::ios::sync_with_stdio(false);

    string a, b;
    cin >> a >> b;

    vector<int> A, B;
    for (int i = a.size() - 1; i >= 0; i--)
    {
        A.push_back(a[i] - '0');
    }
    for (int i = b.size() - 1; i >= 0; i--)
    {
        B.push_back(b[i] - '0');
    }

    vector<int> C;
    if (A >= B)
    {
        C = A - B;
    }
    else
    {
        C = B - A;
        cout << '-';
    }
    for (int i = 0; i < C.size(); i++)
    {
        cout << C[i];
    }
    cout << endl;
    return 0;
}