diff --git a/du1/program b/du1/program
new file mode 100755
index 0000000..b13f1b9
Binary files /dev/null and b/du1/program differ
diff --git a/du1/program.c b/du1/program.c
index e69de29..68631d7 100644
--- a/du1/program.c
+++ b/du1/program.c
@@ -0,0 +1,29 @@
+#include <stdio.h>
+
+
+
+int main(){
+    int c= 0;
+    int n=0; // pocet nacitanych znakov
+    while(1){
+        c = getchar();
+
+        if(c!=-1){ //-1 eof koniec vstupu
+        if( c >= 'a' && c <= 'z'){ //porovnavam cisla v ascii tabulke
+            c=c+'A'-'a';        //velke pismeno na male 
+        }
+        else if(c >= 'A' && c <= 'Z'){
+            c=c-'A'+'a';        //male pismeno na velke
+        }
+        }
+        else{
+            break;
+            }
+        n++;
+        putchar(c);
+
+
+}
+printf("%d\n", n); //vypise pocet zpouzitych znakov
+return 0;
+}
\ No newline at end of file