diff --git a/sherlock_and_the_beast/sherlock_and_the_beast.py b/sherlock_and_the_beast/sherlock_and_the_beast.py
new file mode 100644
index 0000000..736e849
--- /dev/null
+++ b/sherlock_and_the_beast/sherlock_and_the_beast.py
@@ -0,0 +1,25 @@
+#!/usr/bin/python3
+
+# https://www.hackerrank.com/challenges/sherlock-and-the-beast
+
+import sys
+
+def largest_decent_number(num_digits):
+    if num_digits in [1,2,4,7]:
+        return '-1'
+    quot3, mod3 = divmod(num_digits, 3)
+    if mod3 == 0:
+        return '555' * quot3
+    elif mod3 == 1:
+        return '555' * (quot3 - 3) + '3333333333'
+    elif mod3 == 2:
+        return '555' * (quot3 - 1) + '33333'
+
+
+def main():
+    num_tests = int(sys.stdin.readline())
+    for _ in range(num_tests):
+        print(largest_decent_number(int(sys.stdin.readline())))
+
+if __name__ == '__main__':
+    main()
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