diff --git a/a1/program.c b/a1/program.c
index 2a08579..052a19e 100644
--- a/a1/program.c
+++ b/a1/program.c
@@ -7,7 +7,9 @@ void funkcia (int c, int *line_count) {
         putchar(c);
     } else if (isalpha(c)) {
         putchar(islower(c) ? toupper(c) : tolower(c));
-    } 
+    } else if (isprint(c) || c == '\t') {
+        putchar(c);
+    }
 }
 
 int main() {
diff --git a/a1/program.exe b/a1/program.exe
index fc8fc57..2437b24 100644
Binary files a/a1/program.exe and b/a1/program.exe differ