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Contest: Task: Related: TaskA TaskC

Score : $200$ points

Problem Statement

There are $N$ people. The family name and given name of the $i$-th person $(1 \leq i \leq N)$ are $S_i$ and $T_i$, respectively.

Determine whether there is a pair of people with the same family and given names. In other words, determine whether there is a pair of integers $(i,j)$ such that $1 \leq i \lt j \leq N$, $S_i=S_j$, and $T_i=T_j$.

Constraints

$2 \leq N \leq 1000$
$N$ is an integer.
Each of $S_i$ and $T_i$ is a string of length between $1$ and $10$ (inclusive) consisting of English lowercase letters.

Input

Input is given from Standard Input in the following format:

$N$
$S_1$ $T_1$
$S_2$ $T_2$
$\hspace{0.6cm}\vdots$
$S_N$ $T_N$

Output

If there is a pair of people with the same family and given names, print Yes; otherwise, print No.

Sample Input 1

3
tanaka taro
sato hanako
tanaka taro

Sample Output 1

Yes

The first and third persons have the same family and given names.

Sample Input 2

3
saito ichiro
saito jiro
saito saburo

Sample Output 2

No

No two persons have the same family and given names.

Sample Input 3

4
sypdgidop bkseq
bajsqz hh
ozjekw mcybmtt
qfeysvw dbo

Sample Output 3

No