### Round 1

#### 分析

1. S不是偶数（哥德巴赫猜想）。
2. S不是2+素数的形式。

### Round 3

blabla说了一通，不知道说没说明白。语言在表达思想方面还是有点无力，机器翻译成别的语言之后就更不知道变成什么样子了。所以还是扔代码吧：

#!/usr/bin/python

from collections import Counter
from math import sqrt

def crange(a, b):
return range(a, b + 1)

def get_prods(s):
prods = set()
for x in crange(2, s // 2):
return prods

def get_sums(p):
sums = set()
for x in crange(2, int(sqrt(p))):
if p % x == 0:
return sums

def round_one():
prods_cnt = Counter()

for x in crange(2, 99):
for y in crange(x, 99):
prods_cnt[x * y] += 1

prods_rep = set()

for k in prods_cnt.keys():
if prods_cnt[k] > 1:

sums = set()

for s in crange(5, 197):
prods = get_prods(s)
ok = True
for p in prods:
if p not in prods_rep:
ok = False
break
if ok:

return sums

def round_three():
results = []

sums = round_one()
d = dict()
for s in sums:
prods = get_prods(s)
d[s] = prods
for s in sums:
rest = set()
for s2 in sums:
if s == s2:
continue
rest.update(d[s2])
if len(d[s]) - len(d[s].intersection(rest)) == 1:
results.append([s, d[s].difference(rest).pop()])

return results

def org_nums():
results = round_three()
nums = []
for s, p in results:
a = int((s + sqrt(s * s - 4 * p)) / 2)
b = int((s - sqrt(s * s - 4 * p)) / 2)
nums.append([a, b])
return nums

for a, b in org_nums():
print('a = {}, b = {}'.format(a, b))