#include <iostream>

// A note on spelling:
//
// This course generally uses American spelling in its
// instructional material. Thus, we use "kilometer" rather
// than the Canadian spelling "kilometre." In engineering,
// you will frequently communicate with an international
// audience, so consistency and clarity are important.

// The problem:
//
// Ask the user to enter a non-negative integer distance
// in meters and round that distance to the nearest
// kilometer.
//
// If the user enters a negative distance, immediately
// terminate the program by returning 0 from main().
//
// Usually, a remainder of less than 500 m means rounding
// down, while a remainder greater than 500 m means
// rounding up.
//
// If the distance is exactly halfway between two
// kilometers, that is, the remainder is exactly 500 m,
// round to the nearest EVEN number of kilometers.
//
// For example:
//
//     1400 m -> 1 km
//     1600 m -> 2 km
//     2500 m -> 2 km
//     3500 m -> 4 km
//     4500 m -> 4 km
//     5500 m -> 6 km
//
// This method is called "round half to even." You may
// also have heard the rule:
//
//     "Even, leave it; odd, raise it."
//
// Print the resulting number of kilometers.

// Function declarations
int main();

// Function definitions
int main() {
    return 0;
}

























































// Hint:
//
// Begin by using integer division and the remainder
// operator to determine:
//
//     1. the whole number of kilometers, and
//     2. the number of meters remaining.
//
// What should you do when the remainder is
//
//     less than 500?
//     greater than 500?
//     exactly 500?

























































// Here is one solution:

/*
int main() {
    int distance_m{};

    std::cout << "Enter a distance in meters: ";
    std::cin >> distance_m;

    if ( distance_m < 0 ) {
        return 0;
    }

    // Integer division gives the whole number of
    // kilometers.

    int distance_km{ distance_m/1000 };

    // The remainder gives the number of meters beyond
    // that whole number of kilometers.

    int remainder_m{ distance_m%1000 };

    if ( remainder_m > 500 ) {
        // The distance is closer to the next kilometer,
        // so round up.

        ++distance_km;
    } else if ( remainder_m == 500 ) {
        // The distance is exactly halfway between two
        // kilometers. Round to the even number of
        // kilometers.

        if ( distance_km%2 == 1 ) {
            ++distance_km;
        }
    }

    std::cout << "The rounded distance is "
              << distance_km << " km."
              << std::endl;

    return 0;
}
*/