diff --git a/preface.tex b/preface.tex
index 32806cc..b5c8169 100644
--- a/preface.tex
+++ b/preface.tex
@@ -12,7 +12,7 @@ The book is especially intended for
 students who want to learn algorithms and
 possibly participate in
 the International Olympiad in Informatics (IOI) or
-the International Collegiate Programming Contest (ICPC).
+in the International Collegiate Programming Contest (ICPC).
 Of course, the book is also suitable for 
 anybody else interested in competitive programming.