#!/usr/bin/env python3
# Generated by https://github.com/kyuridenamida/atcoder-tools
from typing import *
import collections
import functools
import itertools
import math
import sys

INF = float('inf')
YES = "YES"  # type: str
NO = "NO"  # type: str


def list_uniq_count(l):
    return len(set(l))


def solve(N: int, A: "List[int]"):
    return [NO, YES][list_uniq_count(A) == len(A)]


def main():

    sys.setrecursionlimit(10 ** 6)

    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    print(f'{solve(N, A)}')


if __name__ == '__main__':
    main() from typing import * import collections collections import functools functools import itertools itertools import math math import sys sys INF = float('inf') INF float('inf') float 'inf' YES = "YES" YES "YES" NO = "NO" NO "NO" def list_uniq_count(l):
    return len(set(l)) list_uniq_count return len(set(l)) len(set(l)) len set(l) set l l l def solve(N: int, A: "List[int]"):
    return [NO, YES][list_uniq_count(A) == len(A)] solve return [NO, YES][list_uniq_count(A) == len(A)] [NO, YES][list_uniq_count(A) == len(A)] [NO, YES] NO YES list_uniq_count(A) == len(A) list_uniq_count(A) list_uniq_count A len(A) len A N: int N A: "List[int]" A def main():

    sys.setrecursionlimit(10 ** 6)

    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    print(f'{solve(N, A)}') main sys.setrecursionlimit(10 ** 6) sys.setrecursionlimit sys setrecursionlimit 10 ** 6 10 6 def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
     iterate_tokens for line in sys.stdin:
            for word in line.split():
                yield word
     line sys.stdin sys stdin for word in line.split():
                yield word
     word line.split() line.split line split yield word word tokens = iterate_tokens() tokens iterate_tokens() iterate_tokens N = int(next(tokens)) N int(next(tokens)) int next(tokens) next tokens int(next(tokens)) for _ in range(N) for _ in range(N) _ range(N) range N for _ in range(N) int(next(tokens)) int next(tokens) next tokens A = [int(next(tokens)) for _ in range(N)] A [int(next(tokens)) for _ in range(N)] print(f'{solve(N, A)}') print f'{solve(N, A)}' if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main def main():

    sys.setrecursionlimit(10 ** 6)

    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    print(f'{solve(N, A)}') def main():

    sys.setrecursionlimit(10 ** 6)

    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    print(f'{solve(N, A)}') main YES = "YES" "YES" YES NO = "NO" "NO" NO def solve(N: int, A: "List[int]"):
    return [NO, YES][list_uniq_count(A) == len(A)] def solve(N: int, A: "List[int]"):
    return [NO, YES][list_uniq_count(A) == len(A)] solve def list_uniq_count(l):
    return len(set(l)) def list_uniq_count(l):
    return len(set(l)) list_uniq_count INF = float('inf') float('inf') INF
#!/usr/bin/env python3
# Generated by https://github.com/kyuridenamida/atcoder-tools
from typing import *
import collections
import functools
import itertools
import math
import sys

INF = float('inf')
YES = "YES"  # type: str
NO = "NO"  # type: str


def list_uniq_count(l):
    return len(set(l))


def solve(N: int, A: "List[int]"):
    return [NO, YES][list_uniq_count(A) == len(A)]


def main():

    sys.setrecursionlimit(10 ** 6)

    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    print(f'{solve(N, A)}')


if __name__ == '__main__':
    main()
