#include <iostream>

using namespace std;

int countEvenNumbersBefore(int num) {
    int count = 0;
    for (int i = 0; i <= num; ++i) {
        if (i % 2 == 0) count++;
    }
    return count;
}

int main() {
    int userInput;
    cout << "Please enter a number: ";
    cin >> userInput;

    int result = countEvenNumbersBefore(userInput);
    cout << "Number of even numbers before " << userInput << ": " << result << endl;

    return 0;
}

#include <iostream>
using namespace std;

enum enweekday { sun = 1, mon = 2, tue = 3, wed = 4, thu = 5, fri = 6, sat = 7 };

void showweekday()
{
  cout << "*************************" << endl;
  cout << "*     week day menu     *" << endl;
  cout << "*************************" << endl;
  cout << "(1) sunday." << endl;
  cout << "(2) monday." << endl;
  cout << "(3) tuesday." << endl;
  cout << "(4) wednesday." << endl;
  cout << "(5) thursday." << endl;
  cout << "(6) friday." << endl;
  cout << "(7) saturday." << endl;
  cout << "*************************" << endl;
  cout << "please enter the number of day ?" << endl;
}

enweekday readweekday()
{
  int wd;
  cin >> wd;
  return static_cast<enweekday>(wd);
}

string getweekdayname(enweekday weekday)
{
  switch (weekday)
  {
  case sun:
    return "sunday";
  case mon:
    return "monday";
  case tue:
    return "tuesday";
  case wed:
    return "wednesday";
  case thu:
    return "thusday";
  case fri:
    return "friday";
  case sat:
    return "saturday";
  default:
    return "wrong day";
  }
}

int main()
{
  showweekday();

  cout << "today is " << getweekdayname(readweekday()) << endl;

  return 0;
}

x = int(input("Enter 1st number:"))
y = int(input("Enter 2nd number:"))
z = float(input("Enter 3rd number:"))
n1 = x + y + z
n2 = n1 / 3
n3 = x * y * z
n4 = x - y - z
n5 = x % y % z
print(n1)
print(n2)
print(n3)
print(n4)
print(n5)