Pasha has a wooden stick of some positive integer length *n*. He wants to perform exactly three cuts to get four parts of the stick. Each part must have some positive integer length and the sum of these lengths will obviously be *n*. 

Pasha likes rectangles but hates squares, so he wonders, how many ways are there to split a stick into four parts so that it's possible to form a rectangle using these parts, but is impossible to form a square.

Your task is to help Pasha and count the number of such ways. Two ways to cut the stick are considered distinct if there exists some integer *x*, such that the number of parts of length *x* in the first way differ from the number of parts of length *x* in the second way.
The first line of the input contains a positive integer *n* (1 ≤ *n* ≤ 2·10<sup class="upper-index">9</sup>) — the length of Pasha's stick.
There is only one way to divide the stick in the first sample {1, 1, 2, 2}.

Four ways to divide the stick in the second sample are {1, 1, 9, 9}, {2, 2, 8, 8}, {3, 3, 7, 7} and {4, 4, 6, 6}. Note that {5, 5, 5, 5} doesn't work.
6
1
20
4
1
0
2
0
3
0
4
0
2000000000
499999999
1924704072
481176017
73740586
18435146
1925088820
481272204
593070992
148267747
1925473570
481368392
629490186
157372546
1980649112
495162277
36661322
9165330
1943590793
0
71207034
17801758
1757577394
439394348
168305294
42076323
1934896224
483724055
297149088
74287271
1898001634
474500408
176409698
44102424
1873025522
468256380
5714762
1428690
1829551192
457387797
16269438
4067359
1663283390
415820847
42549941
0
1967345604
491836400
854000
213499
1995886626
498971656
10330019
0
1996193634
499048408
9605180
2401294
1996459740
499114934
32691948
8172986
1975903308
493975826
1976637136
494159283
29803038
7450759
1977979692
494494922
1978595336
494648833
27379344
6844835
1979729912
494932477
1980253780
495063444
1980751584
495187895
53224878
13306219
5
0
7
0
8
1
9
0
10
2
11
0
12
2
13
0
14
3
15
0
16
3
17
0
18
4
19
0
21
0
22
5
23
0
24
5
25
0
26
6
27
0
28
6
29
0
30
7
111
0
55
0
105
0
199
0
151
0
from math import floor

if __name__ == "__main__":
    l = int(input())
    
    if l % 2 != 0:
        print(0)
    elif l % 2 == 0 and l % 4 != 0:
        print(floor(l/4))
    else:
        print((int(l/4 - 1)))
			  	  	   		 	 	  	   		   		