diff --git a/du3/program.c b/du3/program.c
index 1a263e5..6bcc17d 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -1,4 +1,12 @@
 #include <stdio.h>
+#define STACK_SIZE 101
+
+
+struct stack {
+    float values[STACK_SIZE];
+    int size;
+};
+
 
 int main() {
     return 0;