human
An elephant decided to visit his friend. It turned out that the elephant's house is located at point 0 and his friend's house is located at point x(x > 0) of the coordinate line. In one step the elephant can move 1, 2, 3, 4 or 5 positions forward. Determine, what is the minimum number of steps he need to make in order to get to his friend's house.

Input

The first line of the input contains an integer x (1 ≤ x ≤ 1 000 000) — The coordinate of the friend's house.

Output

Print the minimum number of steps that elephant needs to make to get from point 0 to point x.

Examples

Input

5

Output

1

Input

12

Output

3

Note

In the first sample the elephant needs to make one step of length 5 to reach the point x.

In the second sample the elephant can get to point x if he moves by 3, 5 and 4. There are other ways to get the optimal answer but the elephant cannot reach x in less than three moves.
Solve the task in PYTHON3.
 ... What is a Python code to print the minimum number of steps that elephant needs to make to get from point 0 to point x?
assistant
#Here is Python code to print the minimum number of steps that elephant needs to make to get from point 0 to point x.

import functools
import logging
import os
import sys
import time

logger = logging.getLogger()
reader = sys.stdin

# Need to define DEBUGGING variable when run locally
is_judge = os.getenv("DEBUGGING") is None

def timeit(func):
    @functools.wraps(func)
    def timed(*args, **kwargs):
        if is_judge:
            rv = func(*args, **kwargs)
        else:
            ts = time.time()
            rv = func(*args, **kwargs)
            te = time.time()

            logger.debug("performance %r %2.2fms", func.__name__, (te - ts) * 1000)
        return rv
    return timed

# ----------------------
# -     /SOLUTION      -
# ----------------------

@timeit
def main():
    n = int(reader.readline())
    print((n//5) + min(n % 5, 1))

# ----------------------
# -     \SOLUTION      -
# ----------------------

def setup():
    global logger, reader

    if is_judge:
        logger.setLevel(logging.WARNING)
    else:
        # Format logger
        handler = logging.StreamHandler(sys.stdout)
        handler.setLevel(logging.DEBUG)
        formatter = logging.Formatter("{asctime}s - {message}", style='{')
        handler.setFormatter(formatter)

        logger.addHandler(handler)
        logger.setLevel(logging.DEBUG)

        # Stdin from file
        reader = open("input.txt")

if __name__ == '__main__':
    setup()
    try:
        main()
    except KeyboardInterrupt:
        logger.debug("KeyboardInterrupt")
    except IOError as e:
        logger.error(f"I/O error({e.errno}): {e.strerror}")