#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
#define N 1000
//char num1[N], num2[N];
struct BigInteger {
    int mas[N];
    int size;
    bool sign;
    BigInteger(){
    }
    BigInteger(int a) {
        size = a;
        sign = true;
        setZero();
    }
    BigInteger(int  digits[], int sizee) {
        for (int i = 0; i <= sizee; i++) {
            mas[i] = digits[i];
        }
        size = sizee;
    }
    BigInteger(string str) {
        size = str.size() - 1;
        setZero();
        for (int i = 0; i <= size; i++) {
            mas[i] = (str.at(size - i) - '0');
        }
    }
    void setZero() {
        for (int i = 0; i < N; i++) {
            mas[i] = 0;
        }
    }
    bool compareNum(BigInteger num) {
        int maxSize = max(size, num.size);
        for (int i = maxSize; i >= 0; i--) {
            if (mas[i] > num.mas[i]) {
                return true;
            }
            if (num.mas[i] > mas[i]) return false;
        }
        return true;
    }
    BigInteger getSum(BigInteger num) {
        int sizeRes;
        int maxSize = max(size, num.size);
        BigInteger res(0);
        for (int i = 0; i <= maxSize; i++) {
            int x = mas[i]  + num.mas[i];
            res.mas[i] += x;
            res.mas[i + 1] = res.mas[i]/ 10;
            res.mas[i] %= 10;
            sizeRes = i + (res.mas[i + 1] ? 1 : 0);
        }
        res.size = sizeRes;
        return res;
    }
    void print() {
        if (sign == false) cout << "-";
        for (int i = size; i >= 0; i--) {
            cout << mas[i];
        }
    }
    BigInteger getSubtraction(BigInteger num) {
        int x;
        BigInteger res(0);
        int maxSize = max(size, num.size);
        bool maxNum = compareNum(num);
        if (maxNum == false) res.sign = false;
        for (int i = 0; i <= maxSize; i++) {
            if (maxNum == true) {
                x = mas[i] - num.mas[i];
            }
            else x = num.mas[i] - mas[i];
            if (x < 0) {
                res.mas[i] += 10 + x;
                res.mas[i + 1] -= 1;
            }
            if (x == 0) {
                if (res.mas[i] < 0) {
                    res.mas[i] = 10 + res.mas[i];
                    res.mas[i + 1] -= 1;
                }
            }
            if (x > 0) {
                res.mas[i] += x;
            }
        }
        int sizeRes = maxSize;
        int i = maxSize;
        while (i > 0) {
            if (res.mas[i] == 0) {
                sizeRes--;
            }
            if (res.mas[i] != 0) break;
            i--;
        }
        res.size = sizeRes;
        return res ;
    }
};

int main() {
    string str1, str2;
    cin >> str1 >> str2;
    BigInteger a(str1);
    BigInteger b(str2);
    BigInteger c = a.getSubtraction(b);
    c.print();
    return 0;
}