#include <iostream>

int main() {
    int num;
    std::cout << "Enter a number: ";
    std::cin >> num;
    std::cout << "You entered: " << num << std::endl;
    return 0;
}

#include <iostream>
#include <fstream>

int main() {
    std::ofstream outputFile("output.txt");
    if (outputFile.is_open()) {
        outputFile << "Hello, World!" << std::endl;
        outputFile.close();
    } else {
        std::cout << "Unable to open file for writing." << std::endl;
    }
    return 0;
}

#include <iostream>
#include <fstream>
#include <string>

int main() {
    std::ifstream inputFile("input.txt");
    if (inputFile.is_open()) {
        std::string line;
        while (std::getline(inputFile, line)) {
            std::cout << line << std::endl;
        }
        inputFile.close();
    } else {
        std::cout << "Unable to open file for reading." << std::endl;
    }
    return 0;
}