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