diff --git a/README.md b/README.md
index 3aecfef..822f629 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,8 @@
 # Collatz conjecture solver
 ### (x%2==0) ? x/=2 : x=x*3+1;
 
+## You probably want the GMP version for arbitrarily big numbers. Get it from the (GMP branch)[https://git.sdf.org/ilikecats/collatz/src/branch/gmp].
+
 Program to solver the (Collatz conjecture)[https://en.wikipedia.org/wiki/Collatz_conjecture].
 
 Algorithm:
diff --git a/TODO.md b/TODO.md
index 2be3c94..5e4b68c 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,4 +1,3 @@
 # TODO:
--  Use GMP for numbers (to allow for really big numbers)
 -  Make disproving mode
 -  Make no print mode (for speed, implement after disproving mode)
diff --git a/main.cpp b/main.cpp
index 47b404f..c099d0b 100644
--- a/main.cpp
+++ b/main.cpp
@@ -2,7 +2,6 @@
 #include <string>
 
 // TODO:
-//  Use GMP for numbers (to allow for really big numbers)
 //  Make disproving mode
 //  Make no print mode (for speed, implement after disproving mode)