Problem:
Score : 100 points

Problem Statement

Takahashi wants to print a document with N pages double-sided, where two pages of data can be printed on one sheet of paper.

At least how many sheets of paper does he need?

Constraints

N is an integer.

1 \leq N \leq 100

Input

Input is given from Standard Input in the following format:

N

Output

Print the answer.

Sample Input 1

5

Sample Output 1

3

By printing the 1-st, 2-nd pages on the 1-st sheet, 3-rd and 4-th pages on the 2-nd sheet, and 5-th page on the 3-rd sheet, we can print all the data on 3 sheets of paper.

Sample Input 2

2

Sample Output 2

1

Sample Input 3

100

Sample Output 3

50

Solution in Python (3.4.3) (judge verdict: Runtime Error)

bingo = [list(map(int, input().split())) for _ in range(3)]
N = int(input())

for i in range(N):
    b = int(input())
    for j in range(len(bingo)):
            if b == bingo[j]:
                bingo[j] = 0

true_list = list()
for i in [0, 3, 6]:
    if (bingo[i] + bingo[i+1] + bingo[i+2]) == 0:
        true_list.append(0)
for i in [0, 1, 2]:
    if (bingo[i] + bingo[i+3] + bingo[i+6]) == 0:
        true_list.append(0)
if (bingo[0] + bingo[4] + bingo[8]) == 0:
    true_list.append(0)
if (bingo[2] + bingo[4] + bingo[6]) == 0:
    true_list.append(0)

if not all(true_list):
    print('Yes')
else:
    print('No')