#
#  Compute the value of n-factorial for some value of n entered by the user.
#

# Read the value of n from the user
n = int(input("Enter a non-negative integer: "))
original_n = n

# Initialize result to 1
result = 1

# While n is greater than 0
while n > 0:
  # Multiply result by the current value of n
  result = result * n

  # Reduce the value of n
  n = n - 1

# Print the result
print(f"{original_n} factorial is equal to {result}.")