diff --git a/lectures/C_lec03.pdf b/lectures/C_lec03.pdf
new file mode 100644
index 0000000..379ed88
Binary files /dev/null and b/lectures/C_lec03.pdf differ
diff --git a/lectures/C_lec04.pdf b/lectures/C_lec04.pdf
new file mode 100644
index 0000000..44a2c85
Binary files /dev/null and b/lectures/C_lec04.pdf differ