Update Extra

Ashishgup1 · web-flow · commit fec482eeb99d · 2020-07-08T06:05:46.000+05:30
diff --git a/Extra b/Extra
@@ -80,6 +80,7 @@
 
 //Problem 1 (Pending): https://www.codechef.com/ICMT2019/problems/ICM06
 //Problem 2 (Negative base): https://codeforces.com/contest/934/problem/D
+//Problem 3 (Principle of Inclusion Exclusion): https://codeforces.com/contest/1228/problem/E
 
 -Randomized:
 
