diff --git a/a1/program.c b/a1/program.c
new file mode 100644
index 0000000..b466321
--- /dev/null
+++ b/a1/program.c
@@ -0,0 +1,30 @@
+#include <stdio.h>
+
+int main() {
+    int c = 0;
+    int pocet_riadkov = 0;
+
+    while (1) {
+        c = getchar();
+
+        if (c == EOF) {
+            break;
+        }
+
+        if (c >= 'a' && c <= 'z') {
+            c = c - 'a' + 'A';
+        } else if (c >= 'A' && c <= 'Z') {
+            c = c - 'A' + 'a';
+        }
+
+        if (c == '\n') {
+            pocet_riadkov++;
+        }
+
+        // vypis znaku
+        putchar(c);
+    }
+    printf("\nPočet riadkov: %d\n", pocet_riadkov);
+
+    return 0;
+}