编程题：Duplicated Number

It is always a case to find out duplicated data in lab result.

Write a program to read the numbers and figure out if there were any duplicated.

### Input:

The first number is a natural number N, $1\leqslant n\leqslant100000$.
Then there will be N integers.

### Output:

If there are any duplicated number, print out:


YES


Otherwise, print out:


NO


### Sample Input:

in
5
1 2 3 1 4


### Sample Output:

out
YES






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