auto update README.md

Author: Ja2Hw

README.md

@@ -258,6 +258,7 @@
 |17219. 비밀번호 찾기|[링크](./%EB%B0%B1%EC%A4%80/Silver/17219.%E2%80%85%EB%B9%84%EB%B0%80%EB%B2%88%ED%98%B8%E2%80%85%EC%B0%BE%EA%B8%B0/%EB%B9%84%EB%B0%80%EB%B2%88%ED%98%B8%E2%80%85%EC%B0%BE%EA%B8%B0.py)|
 |1764. 듣보잡|[링크](./%EB%B0%B1%EC%A4%80/Silver/1764.%E2%80%85%EB%93%A3%EB%B3%B4%EC%9E%A1/README.md)|
 |17843. 시계|[링크](./%EB%B0%B1%EC%A4%80/Silver/17843.%E2%80%85%EC%8B%9C%EA%B3%84/README.md)|
+|1789. 수들의 합|[링크](./%EB%B0%B1%EC%A4%80/Silver/1789.%E2%80%85%EC%88%98%EB%93%A4%EC%9D%98%E2%80%85%ED%95%A9/%EC%88%98%EB%93%A4%EC%9D%98%E2%80%85%ED%95%A9.py)|
 |18110. solved．ac|[링크](./%EB%B0%B1%EC%A4%80/Silver/18110.%E2%80%85solved%EF%BC%8Eac/README.md)|
 |18111. 마인크래프트|[링크](./%EB%B0%B1%EC%A4%80/Silver/18111.%E2%80%85%EB%A7%88%EC%9D%B8%ED%81%AC%EB%9E%98%ED%94%84%ED%8A%B8/README.md)|
 |1874. 스택 수열|[링크](./%EB%B0%B1%EC%A4%80/Silver/1874.%E2%80%85%EC%8A%A4%ED%83%9D%E2%80%85%EC%88%98%EC%97%B4/%EC%8A%A4%ED%83%9D%E2%80%85%EC%88%98%EC%97%B4.py)|