Petya is having a party soon, and he has decided to invite his $n$ friends.

He wants to make invitations in the form of origami. For each invitation, he needs two red sheets, five green sheets, and eight blue sheets. The store sells an infinite number of notebooks of each color, but each notebook consists of only one color with $k$ sheets. That is, each notebook contains $k$ sheets of either red, green, or blue.

Find the minimum number of notebooks that Petya needs to buy to invite all $n$ of his friends.


-----Input-----

The first line contains two integers $n$ and $k$ ($1\leq n, k\leq 10^8$) — the number of Petya's friends and the number of sheets in each notebook respectively.


-----Output-----

Print one number — the minimum number of notebooks that Petya needs to buy.


-----Examples-----
Input
3 5

Output
10

Input
15 6

Output
38



-----Note-----

In the first example, we need $2$ red notebooks, $3$ green notebooks, and $5$ blue notebooks.

In the second example, we need $5$ red notebooks, $13$ green notebooks, and $20$ blue notebooks.

Difficulty: interview

Starter code:

Solutions:
from math import ceil

n, k = list(map(int, input().split()))

print(ceil((8 * n) / k) + ceil((5 * n) / k) + ceil((2 * n) / k))


n,k=map(int,input().split())
ans=0
ans+=(2*n)//k + bool((2*n)%k!=0)
ans+=(5*n)//k + bool((5*n)%k!=0)
ans+=(8*n)//k + bool((8*n)%k!=0)
print(ans)

from sys import stdin, stdout
from math import sin, tan, cos, pi, atan2, sqrt, acos, atan, factorial

n, k = map(int, stdin.readline().split())
stdout.write(str((n * 2 + k - 1) // k + (n * 5 + k - 1) // k + (n * 8 + k - 1) // k))

n, k = list(map(int, input().split()))
a, b, c = 2 * n, 5 * n, 8 * n
ceil = lambda x, y: (x + y - 1) // y
print(ceil(a, k) + ceil(b, k) + ceil(c, k))


n, k = list(map(int, input().split()))
r_n = n * 2
g_n = n * 5
b_n = n * 8
t = 0
t += r_n // k
if r_n % k != 0:
    t += 1
t += g_n // k
if g_n % k != 0:
    t += 1

t += b_n // k
if b_n % k != 0:
    t += 1
print(t)


N, K= list(map(int, input().split()))
Rcnt = N * 2
Gcnt = N * 5
Bcnt = N * 8

res = (Rcnt + K - 1) // K + (Gcnt + K - 1) //K + (Bcnt + K -1 ) // K
print(res)


import sys
from math import floor, ceil

input = sys.stdin.readline

n, k = map(int, input().split())

print(ceil((n*2)/k) + ceil((n*5)/k) + ceil((n*8)/k))

from math import ceil
n, k = map(int, input().split())
print(ceil(n*2/k) + ceil(n*5/k) + ceil(n*8/k))

n,k = map(int, input().split())

# red = 2
# g = 5
# b = 8
r = (n*2+k-1)//k
g = (n*5+k-1)//k
b = (n*8+k-1)//k
print (r+b+g)

n,k = map(int, input().split())
a = 2*n
b = 5*n
c = 8*n
print((a+k-1)//k + (b+k-1)//k + (c + k -1) // k)

n,k = list(map(int,input().split()))
print((2*n + k - 1) // k + (5*n+k-1) // k + (8*n+k-1)//k)


from math import ceil
n, k = map(int, input().split())
cou = 0
cou += ceil(n*2/k)
cou += ceil(n*5/k)
cou += ceil(n*8/k)
print(cou)

from math import ceil
n,k = list(map(int,input().split()))
print(ceil(n*2/k)+ceil(n*5/k)+ceil(n*8/k))


from math import ceil

n, k = list(map(int, input().strip().split()))
r = 2*n
g = 5*n
b = 8*n

print(ceil(r/k)+ceil(g/k)+ceil(b/k))

''' CODED WITH LOVE BY SATYAM KUMAR '''


from sys import stdin, stdout
import cProfile, math
from collections import Counter
from bisect import bisect_left,bisect,bisect_right
import itertools
from copy import deepcopy
from fractions import Fraction
import sys, threading
sys.setrecursionlimit(10**6) # max depth of recursion
threading.stack_size(2**27)  # new thread will get stack of such size

printHeap = str()
memory_constrained = False
P = 10**9+7
import sys
sys.setrecursionlimit(10000000)

class Operation:
    def __init__(self, name, function, function_on_equal, neutral_value=0):
        self.name = name
        self.f = function
        self.f_on_equal = function_on_equal
def add_multiple(x, count):
    return x * count
def min_multiple(x, count):
    return x
def max_multiple(x, count):
    return x
sum_operation = Operation("sum", sum, add_multiple, 0)
min_operation = Operation("min", min, min_multiple, 1e9)
max_operation = Operation("max", max, max_multiple, -1e9)
class SegmentTree:
    def __init__(self,
                 array,
                 operations=[sum_operation, min_operation, max_operation]):
        self.array = array
        if type(operations) != list:
            raise TypeError("operations must be a list")
        self.operations = {}
        for op in operations:
            self.operations[op.name] = op
        self.root = SegmentTreeNode(0, len(array) - 1, self)
    def query(self, start, end, operation_name):
        if self.operations.get(operation_name) == None:
            raise Exception("This operation is not available")
        return self.root._query(start, end, self.operations[operation_name])
    def summary(self):
        return self.root.values
    def update(self, position, value):
        self.root._update(position, value)
    def update_range(self, start, end, value):
        self.root._update_range(start, end, value)
    def __repr__(self):
        return self.root.__repr__()
class SegmentTreeNode:
    def __init__(self, start, end, segment_tree):
        self.range = (start, end)
        self.parent_tree = segment_tree
        self.range_value = None
        self.values = {}
        self.left = None
        self.right = None
        if start == end:
            self._sync()
            return
        self.left = SegmentTreeNode(start, start + (end - start) // 2,
                                    segment_tree)
        self.right = SegmentTreeNode(start + (end - start) // 2 + 1, end,
                                     segment_tree)
        self._sync()
    def _query(self, start, end, operation):
        if end < self.range[0] or start > self.range[1]:
            return None
        if start <= self.range[0] and self.range[1] <= end:
            return self.values[operation.name]
        self._push()
        left_res = self.left._query(start, end,
                                    operation) if self.left else None
        right_res = self.right._query(start, end,
                                      operation) if self.right else None
        if left_res is None:
            return right_res
        if right_res is None:
            return left_res
        return operation.f([left_res, right_res])
    def _update(self, position, value):
        if position < self.range[0] or position > self.range[1]:
            return
        if position == self.range[0] and self.range[1] == position:
            self.parent_tree.array[position] = value
            self._sync()
            return
        self._push()
        self.left._update(position, value)
        self.right._update(position, value)
        self._sync()
    def _update_range(self, start, end, value):
        if end < self.range[0] or start > self.range[1]:
            return
        if start <= self.range[0] and self.range[1] <= end:
            self.range_value = value
            self._sync()
            return
        self._push()
        self.left._update_range(start, end, value)
        self.right._update_range(start, end, value)
        self._sync()
    def _sync(self):
        if self.range[0] == self.range[1]:
            for op in self.parent_tree.operations.values():
                current_value = self.parent_tree.array[self.range[0]]
                if self.range_value is not None:
                    current_value = self.range_value
                self.values[op.name] = op.f([current_value])
        else:
            for op in self.parent_tree.operations.values():
                result = op.f(
                    [self.left.values[op.name], self.right.values[op.name]])
                if self.range_value is not None:
                    bound_length = self.range[1] - self.range[0] + 1
                    result = op.f_on_equal(self.range_value, bound_length)
                self.values[op.name] = result
    def _push(self):
        if self.range_value is None:
            return
        if self.left:
            self.left.range_value = self.range_value
            self.right.range_value = self.range_value
            self.left._sync()
            self.right._sync()
            self.range_value = None
    def __repr__(self):
        ans = "({}, {}): {}\n".format(self.range[0], self.range[1],
                                      self.values)
        if self.left:
            ans += self.left.__repr__()
        if self.right:
            ans += self.right.__repr__()
        return ans

def display(string_to_print):
    stdout.write(str(string_to_print) + "\n")

def primeFactors(n): #n**0.5 complex 
    factors = dict()
    for i in range(2,math.ceil(math.sqrt(n))+1):  
        while n % i== 0: 
            if i in factors:
                factors[i]+=1
            else: factors[i]=1
            n = n // i 
    if n>2:
        factors[n]=1
    return (factors)
    
def isprime(n):
    """Returns True if n is prime."""
    if n < 4:
        return True
    if n % 2 == 0:
        return False
    if n % 3 == 0:
        return False
    i = 5
    w = 2
    while i * i <= n:
        if n % i == 0:
            return False
        i += w
        w = 6 - w
    return True

def test_print(*args):
    if testingMode:
        print(args)

def display_list(list1, sep=" "):
    stdout.write(sep.join(map(str, list1)) + "\n")

def get_int():
    return int(stdin.readline().strip())

def get_tuple():
    return map(int, stdin.readline().split())

def get_list():
    return list(map(int, stdin.readline().split()))

memory = dict()
def clear_cache():
    nonlocal memory
    memory = dict()
def cached_fn(fn, *args):
    nonlocal memory
    if args in memory:
        return memory[args]
    else:
        result = fn(*args)
        memory[args] = result
        return result


# -------------------------------------------------------------- MAIN PROGRAM
TestCases = False
testingMode = False
optimiseForReccursion = False #Can not be used clubbed with TestCases
            

def main():
    n,k = get_tuple()
    print(math.ceil(2*n/k)+math.ceil(5*n/k)+math.ceil(8*n/k))
    
        
            


# --------------------------------------------------------------------- END


if TestCases: 
    for _ in range(get_int()): 
        cProfile.run('main()') if testingMode else main() 
else: (cProfile.run('main()') if testingMode else main()) if not optimiseForReccursion else threading.Thread(target=main).start()

def ii():
    return int(input())
def mi():
    return list(map(int, input().split()))
def li():
    return list(mi())

n, k = mi()
ans = (n * 2 + k - 1) // k + (n * 5 + k - 1) // k + (n * 8 + k - 1) // k
print(ans)


n, k = map(int, input().split())
print((8 * n + k - 1) // k + (5 * n + k - 1) // k + (2 * n + k - 1) // k)

n,k=list(map(int,input().split()))
print((-(-n*2//k))+(-(-n*5//k))+(-(-n*8//k)))
#2,5,8


import math
n,k  =[*list(map(int, input().split()))]

count = 0

count+= math.ceil(2*n/k)
count+= math.ceil(5*n/k)
count+= math.ceil(8*n/k)
print(count)



from collections import defaultdict
# from fractions import Fraction
def read_line():
    return [int(x) for x in input().split()]

n, k = read_line()

from math import ceil
print(sum(ceil(n*c/k) for c in  [2, 5, 8]))


def mainA():
    n, k = list(map(int, input().split()))
    print((n * 2 + k - 1) // k + (n * 5 + k - 1) // k + (n * 8 + k - 1) // k)

mainA()


from math import ceil 

t = 1#int(input())
for test in range(t):
    n,k = (list(map(int, input().split())))
    (ceil(((n*8)/k)))
    print((ceil(((n*8)/k))) + (ceil(((n*5)/k))) + (ceil(((n*2)/k))))