diff --git a/a1/program.c b/a1/program.c
index e69de29..5184065 100644
--- a/a1/program.c
+++ b/a1/program.c
@@ -0,0 +1,24 @@
+#include <stdio.h>
+#include <ctype.h>
+
+int main() {
+    int ch;
+    int line_count = 0; 
+
+    while ((ch = getchar()) != EOF) {
+        if (islower(ch)) {  
+            putchar(toupper(ch)); 
+        } else if (isupper(ch)) {
+            putchar(tolower(ch)); 
+        } else if (ch == '\n') {
+            putchar(ch);  
+            line_count++; 
+        } else if (ch >= 32 && ch <= 126) { 
+            putchar(ch);
+        }
+    }
+
+    printf("\nPocet riadkov: %d\n", line_count); 
+
+    return 0;
+}