Update i_3_sleeping_125.md

Author: mzhang28

i_3_sleeping_125.md

@@ -1,2 +1,19 @@
 # I <3 SLEEPING (125)
 
+## Problem
+
+We received this string, but I have no idea what it means! `3845281945283805284526053525260547380516453748164748478317454508`
+
+## Hint
+
+ARGH I CAN'T SLEEP PEOPLE KEEP STEALING MY ZZZZs . . . NO MORE ZZZs /cries
+
+P.S. You're overthinking it.
+
+P.P.S. Blocks of 2
+
+Final hint: sqrt(ABCDEFGHIJKLMNOPQRSTUVWXY). Where'd my Z's go?
+
+## External Writeups
+
+*None yet!*