diff --git a/gem_stones/gem_stones.py b/gem_stones/gem_stones.py
new file mode 100644
index 0000000..c3cff06
--- /dev/null
+++ b/gem_stones/gem_stones.py
@@ -0,0 +1,24 @@
+#!/usr/bin/python3
+
+# https://www.hackerrank.com/challenges/halloween-party
+
+import sys
+
+def count_gems(str, gems):
+	tmp = [ False ] * 26
+	for c in str:
+		tmp[ord(c) - 97] = True
+	for i in range(26):
+		if not tmp[i]:
+			gems[i] = False
+
+def main():
+	N = int(sys.stdin.readline())
+	gems = [ True ] * 26
+	for _ in range(N):
+		str = sys.stdin.readline().strip()
+		count_gems(str, gems)
+	print(sum(gems))
+
+if __name__ == '__main__':
+	main()
\ No newline at end of file