Fair Game
Petya and Vasya decided to play a game. They have n cards (n
Before the game Petya will choose an integer and after that Vasya will choose another integer (different from the number that Petya chose). During the game each player takes all the cards with number he chose. For example, if Petya chose number5 before the game he will take all cards on which 5 is written and if Vasya chose number 10 before the game he will take all cards on which 10
The game is considered fair if Petya and Vasya can take all n
Determine whether Petya and Vasya can choose integer numbers before the game so that the game is fair.
Input
The first line contains a single integer n (2 ≤ n ≤ 100) — number of cards. It is guaranteed that n
The following n lines contain a sequence of integers a1, a2, ..., an (one integer per line, 1 ≤ ai ≤ 100) — numbers written on the n
Output
If it is impossible for Petya and Vasya to choose numbers in such a way that the game will be fair, print "NO" (without quotes) in the first line. In this case you should not print anything more.
In the other case print "YES" (without quotes) in the first line. In the second line print two distinct integers — number that Petya should choose and the number that Vasya should choose to make the game fair. If there are several solutions, print any of them.
Example
Input
4 11 27 27 11
Output
YES 11 27
Input
2 6 6
Output
NO
Input
6 10 20 30 20 10 20
Output
NO
Input
6 1 1 2 2 3 3
Output
NO
Note
In the first example the game will be fair if, for example, Petya chooses number 11, and Vasya chooses number 27. Then the will take all cards — Petya will take cards 1and 4, and Vasya will take cards 2 and 3. Thus, each of them will take exactly two cards.
In the second example fair game is impossible because the numbers written on the cards are equal, but the numbers that Petya and Vasya should choose should be distinct.
In the third example it is impossible to take all cards. Petya and Vasya can take at most five cards — for example, Petya can choose number 10 and Vasya can choose number 20. But for the game to be fair it is necessary to take 6
题意：若n个数中有且只有2种不同的个数相同的数。则输出‘YES'，并输出这两个数，否则输出’NO'。比较简单，模拟求解。
Code：
var标签：Vasya,Fair,Petya,Game,number,will,game,cards,Codeforces864A From： https://blog.51cto.com/u_15888102/5878357
n,i,x,t,y,k,p:longint;
a:array[1..100] of longint;
begin
readln(n);
for i:=1 to n do
begin
readln(x);
inc(a[x]);
if a[x]=1 then inc(t);
end;
x:=0;
if t<>2 then writeln('NO') else
begin
for i:=1 to 100 do
if a[i]>0 then
begin
if x=0 then
begin
x:=a[i];k:=i;
end else
begin
y:=a[i];p:=i;
end;
end;
if x=y then
begin
writeln('YES');
writeln(k,' ',p);
end else writeln('NO');
end;
end.