diff --git a/c05_expression/add_one.c b/c05_expression/add_one.c
new file mode 100644
index 0000000..186ad37
--- /dev/null
+++ b/c05_expression/add_one.c
@@ -0,0 +1,16 @@
+/* add_one.c - 递增：前缀和后缀 */
+#include <stdio.h>
+
+int main(void)
+{
+    int ultra = 0, super = 0;
+
+    while (super < 5)
+    {
+        super++;
+        ++ultra;
+        printf("super = %d, ultra = %d\n", super, ultra);
+    }
+
+    return 0;
+}
\ No newline at end of file