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Problems
Contests
National and Regional Contests
China Contests
(China) National High School Mathematics League
2022 China Second Round A1
3
3
Part of
2022 China Second Round A1
Problems
(1)
the existence of a set...or not?
Source: 2022 China Second Round A1 P3
10/30/2022
Does there exist an infinite set
S
S
S
consisted of positive integers,so that for any
x
,
y
,
z
,
w
∈
S
,
x
<
y
,
z
<
w
x,y,z,w\in S,x<y,z<w
x
,
y
,
z
,
w
∈
S
,
x
<
y
,
z
<
w
,if
(
x
,
y
)
≠
(
z
,
w
)
(x,y)\ne (z,w)
(
x
,
y
)
=
(
z
,
w
)
,then
gcd
(
x
y
+
2022
,
z
w
+
2022
)
=
1
\gcd(xy+2022,zw+2022)=1
g
cd
(
x
y
+
2022
,
z
w
+
2022
)
=
1
?
number theory