B - Same Name

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.

3
tanaka taro
sato hanako
tanaka taro

Yes

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

3
saito ichiro
saito jiro
saito saburo

No

No two persons have the same family and given names.

4
sypdgidop bkseq
bajsqz hh
ozjekw mcybmtt
qfeysvw dbo

No