Permission denied (publickey).

계속 이런 문구가 뜹니다...

parkseonsim@bagseonsim-ui-MacBookAir ~ % sudo chmod 400/Users/parkseonsim/Downloads/받은 키.pem

usage: chmod [-fhv] [-R [-H | -L | -P]] [-a | +a | =a [i][# [ n]]] mode|entry file ...

chmod [-fhv] [-R [-H | -L | -P]] [-E | -C | -N | -i | -I] file ...

parkseonsim@bagseonsim-ui-MacBookAir ~ % ssh -i/Users/parkseonsim/Downloads/받은 키.pem 54.180.102.151

parkseonsim@54.180.102.151: Permission denied (publickey).

왜 안될ㄲㅏ요 ㅠㅠ