// Function to calculate the factorial of a number
function calculateFactorial(n) {
  if (n < 0) {
    return "Factorial is not defined for negative numbers.";
  } else if (n === 0 || n === 1) {
    return 1;
  } else {
    let result = 1;
    for (let i = 2; i <= n; i++) {
      result *= i;
    }
    return result;
  }
}

// Example usage
const number = 5;
console.log("The factorial of " + number + " is: " + calculateFactorial(number));