#include <bits/stdc++.h>
#define ll long long
 
using namespace std;
 
string add(string a, string b) {
    // cân bằng độ dài 2 xâu để dễ xử lí
    reverse(a.begin(), a.end());
    reverse(b.begin(), b.end());
    while (a.size() < b.size()) a += '0';
    while (b.size() < a.size()) b += '0';
 
    int r = 0; // số dư
    string ans = ""; // kết quả
    for (int i = 0; i < a.size(); i++) {
        int d = (a[i] - '0') + (b[i] - '0') + r; // tổng từng cặp chữ số từ phải sang trái và thêm nhớ
        r = d / 10; // nhớ bằng kết quả hàng trước chia 10.
        ans += (char)(d % 10 + '0'); // thêm số vừa tính được vào kết quả
    }
 
    if (r) ans += '1'; // nếu còn dư thì thêm vào
    reverse(ans.begin(), ans.end()); // đưa kết quả về đúng thứ tự
 
    return ans; // trả về kết quả
}
 
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
 
    string a, b; cin >> a >> b; // nhập dữ liệu
 
    // kiểm tra số âm
    int plus = 1, pos = 1;
    if (a[0] == '-' || a == "0") pos &= 0, plus ^= 1, a.erase(0, 1);
    if (b[0] == '-' || b == "0") pos &= 0, plus ^= 1, b.erase(0, 1);
 
    if (!plus) cout << "use subtraction" << '\n'; // nếu 2 số trái dấu thì dùng phép trừ
 
    // xuất dữ liệu
    else if (!pos) cout << '-' << add(a, b) << '\n';
    else cout << add(a, b) << '\n';
    return 0;
}

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