#include <iostream>
#include <cctype>

using namespace std;

int main() {
    int userInput;

    cout << "Enter a number: ";
    if (cin >> userInput) {
        cout << "You entered an integer: " << userInput << endl;
    } else {
        cout << "Error: Invalid input. It should be a number." << endl;
    }

    return 0;
}