#include <iostream>
#include <iomanip>
#include <limits>

using namespace std;

int main() {
    int i = 4;
    double d = 4.0;
    string s = "HackerRank ";


    // Declare second integer, double, and String variables.int x;
    int x;
    double y;
    string str;
    // Read and save an integer, double, and String to your variables.
    std::cin >> x;
    std::cin >> y;
    std::cin.ignore();
    getline(std::cin, str);

    // Note: If you have trouble reading the entire string, please go back and review the Tutorial closely.

    // Print the sum of both integer variables on a new line.
    cout << x + i << endl;
    // Print the sum of the double variables on a new line.
    std::cout << std::fixed;
    std::cout << std::setprecision(1);
    cout << y + d << endl;
    // Concatenate and print the String variables on a new line
    // The 's' variable above should be printed first.
    cout << s + str << endl;

    return 0;
}

It work test here